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GENERAL PSYCHOLOGY 
IN TERMS OF BEHAVIOR 



BY 

STEVENSON SMITH, Ph.D. 

PROFESSOR OF PSYCHOLOGY IN THE UNIVERSITY OF WASHINGTON 

AND 

EDWIN R. GUTHRIE, Ph.D. 

ASSISTANT PROFESSOR OF PSYCHOLOGY IN THE UNIVERSITY OF WASHINGTON 




D. APPLETON AND COMPANY 

NEW YORK LONDON 

1921 



V 



COPYKIGHT, 1921, BY 

D. APPLETON AND COMPANY 



PRINTED IN THE UNITED STATES OF AMERICA 

DEC 30 1921 
©GU653309 



PREFACE 

In this book an attempt is made to state in terms of 
behavior the facts and principles of general psychology. 
Although the field it covers is somewhat more extended 
than that of most text-books in psychology, the authors 
have sought to make the book compact as well as sys- 
tematic. For efficiency of teaching much traditional 
but unnecessary detail has been omitted. Only such 
facts of physiology as have important significance in an 
introductory course are included. Many blind-alley 
topics, an acquaintance with which has been considered 
a polite accomplishment in psychology, have been de- 
liberately disregarded. The facts set forth are those 
which lead the student to a systematic explanation of 
his own conduct and that of his fellows. The purpose 
of the book is to describe man's original nature, the 
way in which this nature is altered by use, and the com- 
mon modes of individual and social behavior that result. 

S. S. 

E. R. & 



p> 



CONTENTS 

PAGE 

Preface v 

CHAPTER 

I. The Elements of Behavior 1 

Behavior Dependent on Bodily Structure . . . 3 

Classes of Sense Organs 6 

The Exteroceptors 7 

The Interoceptors . .20 

The Proprioceptors . .21 

The Nervous System 23 

Regulatory Character of Responses .... 28 

Delayed Utility of Responses 31 

Apparent Absence of Utility of Some Responses . 32 

Orientation, Locomotion, and Intervention ... 33 

Internal Responses 36 

The Action of a Stimulus-Response Mechanism . . 39 

Weber's Law 42 

The Interaction of Stimulus-Response Mechanisms . 43 

Compromise Responses 46 

II. Instinct . . 48 

Reflexes 49 

Instincts Are Chain Reflexes 54 

Precurrent and Consummatory Responses ... 60 
The Effect of Varying Situations upon Precurrent 

Responses 67 

^Individual Differences ....... 70 

III. Learning 75 

Positive Adaptation 76 

Negative Adaptation 80 

Transitory Changes of Threshold during a Single 

Practice Period 85 

Initial Torpor and Fatigue .85 

The Conditioned Response 88 

Conditioned Emotional Responses 91 

The Substitution of Similar Stimuli . . . .94 

Facilitating Effect of Conditioning Stimuli ... 95 
vii 



viii CONTENTS 

CHAPTER PAGE 

The Neural Basis of Learning? 97 

Associative Inhibition 99 

The Serial Response 100 

The Effects of Practice on the Serial Response . . 105 

Forgetting 109 

Whole and Part Learning 113 

Results of the Distribution of Practice . . . 115 

Learning Meaningful Material 116 

Trial and Error .117 

The Shortening of a Trial and Error Series into a 

Final Habit Response 119 

Imitation 130 

IV. CCENOTROPES 134 

Common Habits . 138 

Both Instincts and Ccenotropes Are Common Modes 

of Behavior 145 

Play 148 

Other Examples of Common Modes of Behavior . 153 

V. Perception 158 

Perception and Speech . .... 162 
At Different Times a Situation May Prompt Us to 

Different Perceptions 166 

Compromise Responses in Perception . . ... 170 

Perceptions from Simultaneous Stimuli . . . 171 

Space Perception 172 

Visual Space Perception 173 

Visual Perception of Objects 178 

Auditory Space Perception 180 

Auditory Perception of Objects 181 

Olfactory Perception 183 

Kinsesthetic and Static Perception .... 186 

Touch Perception 186 

Time Perception . 187 

Judgment 190 

Conviction and Belief 195 

VI. Human Motives 198 

The Delayed Reaction 198 

The Wish 203 

Attention 204 

Volition 205 

Intention . . . .209 

Drive 210 



CONTENTS ix 

CHAPTER PAGE 

Sublimation 214 

Conflict . 216 

Over-correction 218 

VII. Social Psychology 220 

Fellow Man as a Constant Situation .... 220 

Other Prevalent Situations 221 

Formation of Habits in Common 224 

The Spread of Tradition 232 

Opinion Spreads from Mouth to Mouth . . . 236 

Human Institutions 237 

APPENDIX 

Consciousness 243 

Consciousness and the Nervous System . . . 245 

Sensation 245 

Emotion and Affection 250 

Images 250 

Association of Ideas 252 

Imagination 255 

Attention 256 

Perception 257 

The Unconscious . . . . . . . . 258 

Bibliography 261 

Index 265 



ILLUSTRATIONS 

FltfURB PAOB 

1. Schematic Diagram of a Section through the Eye . 9 

2. Diagram of the Position of the External Muscles That 

Move the Eyeball 10 

3. Schematic Representation of a Section through the 

Retina, Showing the Position of Rods and Cones, 
the Layer of Connecting Neurones, and the Direc- 
tion of Fibers of the Optic Nerve .... 13 

4. Drawing from a Model of the Inner Ear, Showing 

the Cochlea, in Which Are the Sense Organs of 
Hearing; the Utricle and Saccule, the Organs of 
Static Sense; and the Semi-circular Canals . . 15 

5. Schematic Section through One of the Coils of the 

Cochlea, Showing the Basilar Membrane and Ad- 
jacent Structures 16 

6. Section through the Olfactory Membrane Showing Ol- 

factory Cells and Supporting Cells .... 17 

7. Touch Corpuscle from the Palm of the Human Finger 13 

8. The Relation of Efferent Fibers of the Autonomic and 

the Peripheral Nervous Systems to the Central 
Nervous System . 24 

9. Schematic Section of the Spinal Cord .... 25 

10. Schematic Representation of Sensory Neurone . . 26 

11. Schematic Representation of Motor Neurone ... 27 

12. Scheme of Neural Pathways from a Sense Organ in the 

Skin to a Muscle 29 

13. Diagrammatic Representation of the Chain Reflex 

Mechanism . 56 

14. Distribution of Unselected Group of Runners . . 71 

15. Surface of Frequency Showing the Distribution of the 

Runners of Figure 14 According to their Time in 
Seconds 71 

16. Distribution of Alpha Test Scores for College Students 

and for the Draft Army 73 

xi 



xii ILLUSTRATIONS 

FIOUBK PAOE 

17. Distribution of Alpha Test Scores for Various Groups 

in the Draft Army 73 

18. Curve of Practice in Mirror Drawing .... 78 

19. Distribution of German Industrial Accidents through- 

out the Working Day, in Part the Result of 
Fatigue 87 

20. Establishing a Conditioned Response .... 98 

21. Diagrammatic Representation of the Formation of a 

Serial-Response Habit 104 

22. The Number of Repetitions Required for Establishing 

Serial Responses of Various Lengths . . . 106 

23. The Actual Amount of Work Done in Order to Learn 

the Series of Various Lengths 107 

24. The Time Saved in Relearning a Serial Response of 16 

Nonsense Syllables Shown as a Function of the 
Amount of Yesterday's Practice .... 110 

25. The Rate of Forgetting a Nonsense Series ... . Ill 

26. Staircase Figure 168 

27. The Cube Face that is Perceived as Nearest the Ob- 

server may also be Perceived as the Most Distant . 169 

28. A Pear is Perceived as behind an Apple because it is 

Partially Hidden by the Apple 176 

29. Objects Higher in the Field of Vision tend to be Per- 

ceived as More Distant 177 

30. Respiratory Antecedents of Voluntary Movement . . 208 



GENERAL PSYCHOLOGY 
IN TERMS OF BEHAVIOR 



GENERAL PSYCHOLOGY 

IN TERMS OF BEHAVIOR 



CHAPTER I 



THE ELEMENTS OF BEHAVIOR 



Psychology takes the common sense view that any 
animal is a physical object in a world of physical 
objects. It assumes that all these objects act upon 
each other in the ways described by physics, chem- 
istry, and physiology. It considers man's behavior 
as a physical event that can be analyzed into bodily 
movements. In this sense man's behavior is me- 
chanical and his body is a machine. 

The behavior of animals does not involve new and 
mysterious forces lacking elsewhere in nature, even 
though it is true that anjmimaPs structure is too 
complex to be duplicated, and though any attempt 
to construct a machine that would respond as elab- 
orately and appropriately as do animals to the world 
of surrounding objects must certainly fail. 

It must not be supposed that thinking is denied 
by physiological psychology. A behavioristic de- 
scription of man's mind in no way contradicts the 
common sense assumption that men are conscious. 
We shall first find out what man does, and under 

l 



2 GENEEAL PSYCHOLOGY 

what circumstances he does it, because this is open 
to observation and may be stated exactly. 1 An un- 
derstanding of behavior is essential to an under- 
standing of consciousness. 

All that we can observe in our fellow man is his 
behavior. He moves his body and its appendages 
as he goes from place to place or as he rearranges 
the objects about him. In conversation he contracts 
the necessary muscles and is heard to speak. In 
emotional expression he blushes, his pulse is altered, 
his hands grow cold, his liver gives up its sugar, 
and we see shame, anxiety, or anger. His thoughts, 
as such, are known to no one but himself. 

Any physical object is at all times being acted 
upon by forces that affect it in various ways. The 
stone lying in the road is moved about by the im- 
pact of rain, warmed and expanded by the sun, and 
scratched by the wheels of passing vehicles. Its 
responses to these forces are simple and easily pre- 
dicted because of the simplicity of its structure. 

If we consider not only the stone in the road but 
also the gopher who sits beside it, we find the same 
forces acting. The light reflected from surrounding 
objects falls on both alike, both are struck by the 
rain or warmed by the sun, but the result of the 
action of these forces on the gopher is behavior quite 

i The first systematic statement that mind could be described in 
terms of behavior was made by Dr. E. A. Singer, Jr., in 1911. See 
articles: "Mind as an Observable Object," Journal of Philosophy, 

1911, p. 180, and 1912, p. 206; "Consciousness and Behavior," ibid., 

1912, p. 15; "The Pulse of Life," ibid., 1914, p. 645; "On Sensibil- 
ity," ibid., 1917, p. 337. 



THE ELEMENTS OF BEHAVIOR 3 

different from the behavior of the stone. The light 
rays reflected from the approaching vehicle cause 
him to scurry away and those reflected from 
food cause him to approach. The impact of rain 
may move him toward the source of impact rather 
than away from it. Though, like the stone, he is a 
physical object, he is not merely buffeted about by 
his environment. 

Behavior Dependent on Bodily Structure 

The difference between the behavior of animals 
and the behavior of inanimate objects depends upon 
the fact that animals possess specialized structures. 
The most important of these structures are the sense 
organs (receptors), the muscles and glands (effec- 
tors), and the nervous system. The sense organs are 
placed in parts of the body where they are exposed 
to the action of physical forces. The physical forces 
that arouse, the sense organs to action are called 
stimuli. Because the various kinds of sense organs 
differ from each other in structure, some are pro- 
voked to action by one kind of physical force, and 
some by another. 

The stimulus that commonly arouses the sense 
organ to its characteristic function is called the ade- 
quate stimulus. Light has an effect upon the eye 
that it does not have upon the ear or upon the skin. 
Gases emanating from a flower act only upon the 
olfactory sense organs. In addition to their more 



4 GENEEAL PSYCHOLOGY 

frequently received stimuli, many sense organs may 
be stimulated by pressure or by an electric current. 

The physical forces that stimulate the sense or- 
gans differ in kind. Light, heat, gravity, sound, 
and impact, are a few of these and each acts upon 
some sense organ or another. All stimuli may vary 
in intensity, and their effect upon sense organs may 
vary correspondingly. 

Sense organs are connected with distant muscles 
and glands by nerve structures. Along these nerve 
structures pass nervous impulses which result from 
the stimulation of the sense organs and which, on 
reaching muscles and glands, may cause muscular 
contraction or glandular secretion. It follows that 
any response to a stimulus can occur only when 
there is a conduction pathway established between 
the sense organ receiving the stimulus and the 
muscles concerned in the response. Such a pathway 
is called a neural arc. 

The nervous system contains millions of nerve 
cells called neurones. These are microscopic in 
cross-section but are occasionally as much as two 
feet or more in length. Each neurone consists of a 
cell body from which extend branching processes 
which may lie adjacent to other cells. The points of 
contact so established offer varying resistance to the 
passage of nervous impulses from one cell to an- 
other. Such a connection between two neurones 
that permits the passage of a nervous impulse is 
(palled a synapse. The repeated passage of an im- 



THE ELEMENTS OF BEHAVIOR 5 

pulse through a synapse is supposed to increase the 
conductivity of the synapse. Some synapses are 
present at birth, some occur in the maturation of the 
nervous system, whereas others are formed in the 
course of learning. 

The great number of neurones and the complexity 
of their connections account for the fact that an im- 
pulse leaving a particular sense organ may find its 
way to one group of muscles at one time and to 
another group of muscles at another time. 

The muscles and glands are the effectors, or or- 
gans of response. They are so situated and so con- 
nected with sense organs by nervous structures that 
their responses are coordinated and meet suitably 
most situations. Placing something in a baby's hand 
causes the hand to grasp the object. The nervous 
impulse that starts from sense organs in the skin 
finds its way to the muscles which cause the fingers 
to close. Without such established pathways of con- 
duction, behavior would be inappropriate. 

A significant characteristic of all sense organs is 
that they are most sensitive to situations that affect 
the life processes of the animal. This adjustment to 
situations depends, first, upon the position of the 
sense organs in the body, and second, upon the 
structure of the sense organs and upon the nature 
of their adequate stimuli. For example, the eyes are 
so placed in the front of the body as to receive stim- 
uli from objects which the animal is approaching. 
Placed at the rear they would be less useful. The 



6 GENERAL PSYCHOLOGY 

tongue has a strategic position, as all food must pass 
its inspection before being swallowed, and the sense 
organs of taste are affected as are no other parts of 
the body by the chemical stimuli that are indicative 
of the food value of any substance taken into the 
mouth. 

Classes of Sense Organs 

According to their location in the body, sense or- 
gans are described as the exteroceptors, the intero- 
ceptors, and the proprioceptors. 2 Those on the outer 
surface of the body, which receive external stimuli, 
are called exteroceptors. These are the sense or- 
gans in the skin that respond to touch, temperature, 
and destructive stimuli, and along with these the 
sense organs in the eyes, ears, and nose. The eyes, 
ears, and nose are also called distance receptors be- 
cause they respond to stimuli whose origin is com- 
monly at a distance, a classification recognized by 
as early a writer as Aristotle. 8 

Besides the external surface of the body there 
is the surface of the enteric tract, which consists of 
the mouth, pharynx, oesophagus, stomach, and in- 
testines. This surface is also provided with sense 
organs and these are called inter o cept or s. Parts of 
the external world taken into the enteric tract, 
usually as food, stimulate the interoceptors and the 
animal's behavior is adjusted to what has been 

2 Sherrington, The Integrative Action of the Nervous System, 
lecture 9. 

3 Aristotle, De Sensu, 436b. 



THE ELEMENTS OF BEHAVIOR 7 

swallowed. The mouse that is outside a cat stimu- 
lates the cat's exteroceptors and the cat responds in 
a conspicuous and characteristic way. Once the 
mouse is transferred to the cat's enteric tract, the 
cat's reactions are less obvious but none the less im- 
portant. Movements of rejecting food, of swallow- 
ing, and of peristalsis, the secretion of digestive 
fluids, and much of the animal's observable be- 
havior result directly from the stimulation of intero- 
ceptors. 

Sense organs occur not only on the outer and the 
inner surfaces of the animal but are also found 
deeply imbedded in the body tissue. These deeply 
imbedded sense organs are called proprioceptors. 
Among the contractile muscle fibers are situated re- 
ceptors that are stimulated by muscle tension. Other 
receptors in the tendons receive stimuli in a similar 
way. The walls of blood vessels are supplied with 
sense organs, so that circulatory changes affect the 
animal's behavior. In the head are located the semi- 
circular canals and the organs of static sense, which 
are stimulated by the movement or by the position 
of the animal. The proprioceptors are all-important 
in making possible the coordination of bodily move- 
ments. 4 

The Exteroceptors 
The most highly developed of the exteroceptors 

* On the classes of sense organs and their functions see Sherring- 
ton, op. cit. 



8 GENERAL PSYCHOLOGY 

are the distance receptors, namely the organs of 
vision, hearing, and smell. 5 

The Eye, — Anyone having an acquaintance with 
the camera will find it easy to understand the me- 
chanism of the eye. Light passes into the eye 
through the anterior wall, which is the transparent 
cornea. Behind the cornea is a diaphragm called 
the iris. Behind the iris is the lens and behind the 
lens, on the inner surface of the eye's globe-like 
wall, is the sensitive retina. The internal cavity of 
the eye is filled with a transparent mass. That in 
front of the lens is called the aqueous humor and 
that behind the lens, the vitreous humor. As we 
view our own eye in the mirror we see at the center 
a black spot, the pupil, surrounded by a pigmented 
ring, the iris. The pupil is a hole in the iris and ap- 
pears black because it is an opening into the un- 
lighted interior of the eye. It is the color of the iris 
to which we refer when we speak of brown eyes or 
blue eyes. Outside the circle of the iris is the white 
sclerotic, continuous with the cornea, which, with 
the cornea, constitutes the external wall of the eye. 
(See Figure 1.) 

By means of six external muscles the eyeball is 
moved about in its socket, and in this way a person 
looks up or down, to the right or the left, converges 
the two eyes in fixating a near object or so directs 
them that the axes of vision (the lines passing 

s For a more detailed account of the structure and function of 
sense organs and nervous system see Ladd and Wood worth, Elements 
of Physiological Psychology. 



THE ELEMENTS OF BEHAVIOR 9 

through the center of the cornea, pupil, lens, and 
fovea) are almost parallel in fixating a distant ob- 
ject. To some extent the eye may b6 rotated about 
the axis of vision. (See Figure 2.) 

The iris is a doughnut-shaped muscle containing, 
for the most part, circular muscle fibres. When 



CillQ7TJ* 

muscle 



Choroid 




Figure 1. schematic diagram of a section through the eye 



these fibres contract, the hole in the center, the pupil, 
becomes smaller. When the radiating fibres that it 
contains contract, the pupil becomes larger. For 
near vision and when stimulated by bright light, the 
pupil becomes smaller. For distant vision and in 
dim light the pupil becomes larger. 

The crystalline lens is suspended all around its 
margin by the suspensory ligament which connects 



10 



GENERAL PSYCHOLOGY 



it with a second doughnut-shaped muscle called the 
ciliary muscle. When the circular fibres of this 
muscle contract, the tension on the suspensory liga- 
ment is decreased and, because it is itself elastic, 
the lens becomes more convex. In this shape it fo- 
cuses rays of light from nearby objects so that the 




INFERIOR 
QBUQVE 

FlGUBE 2. DIAGRAM OF THE POSITION OF THE EXTERNAL MUSCLES THAT 
MOVE THE EYEBALL 



images of these objects are clearly defined on the 
retina and the images of distant objects are blurred. 
When the circular fibres of the ciliary muscle are 
relaxed and the radial fibres contracted, the suspen- 
sory ligament is under greater tension, so that the 
lens becomes less convex and the images of distant 
objects are clearly defined on the retina, the images 
of nearby objects being blurred. When the eyelids 
are closed and the eye is at rest, the circular fibres 
are relaxed and the lens takes on this less convex 



THE ELEMENTS OF BEHAVIOR 11 

shape, that is, the eye is accommodated for distant 
vision. 

Accommodation for near vision, then, involves a 
smaller hole in both the iris and the ciliary muscle 
and this is brought about by the contraction of the 
circular fibres in each. For this reason accommo- 
dation for near vision, because of the stimulation 
of sense organs in these muscles, gives us a sensa- 
tion of muscle strain. In distant vision and dim 
light, where the circular fibres are relaxed, such sen- 
sations are practically absent. 

The adequate stimuli to the eye are ether vibra- 
tions whose frequency is more than 450 million mil- 
lion vibrations per second and less than 790 million 
million. Lights of different color have different vi- 
bration frequencies and intense lights have a greater 
amplitude of vibration than have dim lights. White 
sunlight contains a mixture of rays of all possible 
vibration frequencies to which the eye is sensitive. 
Light emanating from a source such as the sun or a 
candle either enters the eye directly or impinges 
upon the surfaces of objects from which it is re- 
flected into the eye. 

Light passing through the cornea, the aqueous 
humor, the lens, and the vitreous humor reaches the 
retina. In the retina are found chemical substances 
that change their composition when acted upon by 
light, and cell structures, some of which are affected 
by these chemical changes. Exactly what takes place 
in the retina is not known, but we have reason to 



12 GENERAL PSYCHOLOGY 

believe that the pattern of the image focussed upon 
the retina sets up various changes in the photo- 
chemical substances and that these changes affect/ 
adjacent cell structures. This is the stimulation that 
gives rise to nervous impulses. 

Apart from supporting tissue, the cell structure 
of the retina is made up of nerve-cell bodies whose 
long processes, or axones, constitute the optic nerve ; 
of other nerve cells whose function it is to connect 
adjacent parts and layers of the retina; and of the 
rods and cones, which may be regarded as the actual 
sense organs for vision. (See Figure 3.) The rods 
respond to dim light as well as to intense light, 
whereas the cones respond only to intense light. 
Colored light and white light affect the rods in the 
same way, no color vision resulting from such stim- 
ulation. 6 On the other hand the cones give a special- 
ized response to white light and to lights of different 
colors, and it is by means of the cones that we dis- 
tinguish one color from another. 

The rods are lacking in the fovea, or that portion 
of the retina that is directly opposite the pupil. At 
night when an image of a faint star falls upon the 
fovea, where there are no rods, it cannot be seen, 
but it becomes visible when we glance to one side 
and so cause its image to be displaced toward the 
periphery, which is well supplied with these sense or- 
gans for dim light. The fovea is richly sup- 
plied with cones and is the so-called area of distinct 

e For the various theories of color vision see ibid., pp. 340ff. 



THE ELEMENTS OF BEHAVIOR 



13 



vision. The image of the print which is being read 
falls upon the fovea, and the print could not be read 
as well if its image were to fall npon the peripheral, 
or outer, margin of the retina. The extreme periph- 



Direction 



~"fc& Ganglion 




Pigment layer 



7b Brain 



Figure 3. schematic representation of a section through the 

retina, showing the position of rods and cones, the layer of 

connecting neurones, and the direction of 

fibres of the optic nerve 

ery contains only rods, and for this reason any 
object casting its image there appears to be without 
color. 

When the eye has been exposed to intense light the 
rods become fatigued and do not function in twilight 
until after a period of rest. For this reason, if we 
enter a darkened theater in the daytime, we grope 



14 GENERAL PSYCHOLOGY 

blindly for the seat, but if we have come in from 
the dimly lighted street at night, we find our way 
about without difficulty. In the dark-room it may 
require a stimulus 8,000 times as great to elicit a re- 
sponse from a light-fatigued eye as is required to 
secure a response from the thoroughly rested eye. 
This is true, of course, only of parts of the retina 
where rods are found The unfatigued eye is some- 
times ambiguously called a "dark-adapted" eye. 

Ordinarily both eyes are used in vision, and are 
so directed toward a part of any object that is looked 
at that the right eye image and the left eye image 
fall on corresponding areas of the two retinae. 
When this occurs, the two images appear as one, 
and are said to fuse. When the two images fall 
on non-corresponding parts of the two retinae, 
the object is seen double. In order that the images 
from a near object may fall on corresponding parts 
of the two retinae the eyes must be so moved that 
the axes of vision converge. To secure fusion 
of the images of a distant object, the eyes must 
be so directed that their axes of vision are almost 
parallel. 

An important fact is that vision enables animals to 
respond to objects at a distance. 

The Ear. — Three parts of the ear are distin- 
guished, the external, the middle, and the internal 
ear. The external ear leads into the middle ear and 
is separated from it by the tympanic membrane. 
When air vibrations impinge upon this membrane, it 



THE ELEMENTS OF BEHAVIOK 15 

oscillates back and forth and causes movement in a 
series of three small bones situated in the middle 
ear. The movement of these bones is transmitted 
in turn to the fluid in the cochlea, which is a part of 
the inner ear. Thus vibrations are set up in this 
fluid that have the same rate as the air vibrations 

Semicircular 
canal 



Ampulla 




Ampulla 



Figure 4. drawing from a model of the inner ear, showing the 

cochlea, in which are the sense organs of hearing; the utricle 

and saccule, the organs of static sense; and 

the semicircular canals 



outside. The endings of a part of the auditory 
nerve are situated along the base of a row of rods 
and hair cells that project into the fluid contained in 
the cochlea. (See Figures 4 and 5.) It is not cer- 
tain whether the auditory nerve endings are stimu- 
lated by the vibration of this projecting row or by 
the vibration of the membrane at the base of the 
row. 



16 



GENERAL PSYCHOLOGY 



The adequate stimuli to the ear are vibrations in 
the surrounding medium, usually in the atmosphere. 
These are condensation and rarefaction vibrations 
and their rate varies from something more than 16 
per second to about 50,000 per second. Sound ema- 
nates from a vibrating object, such as a bell or the 




Figure 5. schematic section through one of the coils of the 

cochlea, showing the basilar membrane and 

adjacent structures 

vocal cords- of an animal, and the vibrations are 
taken up by the atmosphere and conveyed to the 
tympanic membrane. This enables an animal to re- 
spond to objects at a distance. 



THE ELEMENTS OF BEHAVIOR 



17 



The Nose. — In the wall of a recess that opens upon 
the air passages of the nose are found the sense or- 
gans for odor. The actual sense organs for odor are 
long nerve cells embedded between epithelial cells 
and with long processes extending to the surface of 
the mucous membrane. In the other direction nerve 
fibres extend from these cells to the brain. (See 
Figure 6.) 



Olfactory 
cell 




Epithelial 
cell 



Figure 6. 



SECTION THROUGH THE OLFACTORY MEMBRANE SHOWING 
OLFACTORY CELLS AND SUPPORTING CELLS 



The adequate stimuli to the olfactory sense organs 
are gases in the atmosphere. These emanate from 
volatile substances, and upon reaching the nose are 
inhaled past the olfactory area. This makes it pos- 
sible for the animal to respond to objects at a dis- 
tance, although the stimulus may be slow in reach- 
ing the animal and gives but little indication of the 
direction of its source. 

Organs of Touch. — There are two kinds of sense 
organs for touch. On parts of the body where hair 
is absent, such as the lips and the palm of the hand, 



18 GENERAL PSYCHOLOGY 

are found touch corpuscles that enclose a core of 
cells and nerve fibres. On the hairy surfaces the 
nerve fibres are found coiled about the roots of the 
hairs. The touch corpuscles (shown in Figure 7) 
are plentiful in some areas of the skin such as lips, 
tongue, and finger tips, and sparsely distributed in 
other areas. 

The adequate stimulus for touch is deforming 



\ Branching 
^endof 
Sensory 
neurone 




FlGUEE 7. TOUCH CORPUSCLE FROM THE PALM OF THE HUMAN FINGER 
(AFTER RANVIER) 

pressure upon the skin adjacent to a corpuscle, or 
to the "windward" of a hair, or pressure upon the 
hair itself, which stimulates the nerve ending at its 
roots. 

Warmth Organs. — The warmth sense organs are 
probably distinct from the cold sense organs. This 
conclusion is suggested by the fact that spots on the 
skin sensitive to warmth are much fewer than spots 
sensitive to cold. There are, on the average, two 
or three such warmth spots to the square centimeter 
of skin surface. The organ is probably a cylindrical 
end bulb found rather deeply imbedded in the skin. 



THE ELEMENTS OF BEHAVIOR 19 

The adequate stimulus for warmth is anything 
that increases within certain limits the temperature 
of the sense organ. This may be done by the con- 
tact of the skin with objects whose temperature is 
higher than that of the sense organ at the time, by 
radiant heat emanating from objects at a distance, 
and by the dilatation of neighboring blood vessels. 
Dilatation may be produced by the application to 
the skin of such substances as mustard or pepper. 

Cold f Organs. — The sense organs for cold prob- 
ably have the form of end bulbs, lying nearer the 
surface of the skin than do the warmth organs. The 
spots sensitive to cold average between 10 and 15 
per square centimeter of skin surface. 

The adequate stimulus for cold is anything that 
reduces within certain limits the temperature of the 
sense organ. This may be done by the contact of the 
skin with objects whose temperature is lower than 
that of the sense organ at the time, by skin evapora- 
tion, by heat radiation from the skin, and by the con- 
striction of neighboring blood vessels. Certain sub- 
stances, such as menthol, stimulate the cold organ 
either by direct action or possibly by causing blood- 
vessel constriction. A cold spot, curiously, may be 
stimulated by a pointed hot rod of a temperature 
45 to 50 degrees C. (The temperature of the blood 
is 37 degrees 0.)- When such a result is obtained, 
we have what is called paradoxical cold. 

Pain Organs. — Certain free nerve endings that 
are found distributed over most of the body surface 



20 GENERAL PSYCHOLOGY 

are probably sense organs for pain. Pain is also 
elicited by the stimulation of parts of the body other 
than the skin surface, and possibly results from the 
intense stimulation of sense opgans not primarily 
concerned with pain. 

The adequate stimuli to the pain organs are me- 
chanical, thermal, and chemical, and must be of 
much greater intensity than those that are neces- 
sary to arouse the organs of touch and temperature. 
The prolongation of these intense stimuli is usually 
injurious to the animal. 

The Interoceptors 

Taste Organs. — The receptors for taste are situ- 
ated on the upper surface and the margin of the 
tongue, a few occurring on the uvula, the epiglottis, 
and the larynx. They are in the form of end bulbs 
penetrated by the sensory nerve ending and having 
a minute opening on the external surface. They are 
grouped together in certain of the papillae of the 
tongue, which are easily observed as small emi- 
nences. 

The adequate stimuli for taste may be divided 
into four classes according to the responses they 
elicit: sweet, sour, salt, and bitter substances, and 
there are probably four corresponding kinds of taste 
organs. In order to stimulate the organs, the sub- 
stance must be soluble. Many substances such as 
peppermint, onion, cantaloupe, or cheese are popu- 
larly regarded as having characteristic tastes, but 



THE ELEMENTS OF BEHAVIOR 21 

these are for the most part odors. When the nose 
is carefully packed, so that no respired air reaches 
the olfactory surface, it is impossible to distinguish 
clam bouillon from beef bouillon, black coffee from 
quinine solution, honey from molasses, or lemon 
juice from vinegar. These substances are then re- 
sponded to as though they were merely salt, bitter, 
sweet, or sour. 

Other Interoceptors. — Sense organs are found 
throughout the mucous membrane of the alimentary 
tract. Because of their isolated position, less is 
known concerning their action than is known of the 
function of sense organs more accessible to experi- 
mentation. They are more sparsely distributed 
than are the sense organs on the skin and, though 
some respond to pressure and to temperature, they 
are most affected by chemical stimuli. 

Their adequate stimuli are food substances, inter- 
nal secretions, and the movements of the enteric 
tract. Thirst results from dryness of the pharynx, 
and hunger from a vigorous peristaltic movement 
of the empty stomach that may occur at intervals of 
about one minute. 

The Proprioceptors 

Semicircular Canals. — These organs, though not 
auditory in function, are contained in three com- 
municating cavities constituting a part of the inner 
ear. (See Figure 4.) The cavities are, roughly 
speaking, ringlike in form, each one being set at 



22 GENERAL PSYCHOLOGY 

right angles to the other two. Cells with hairlike 
processes project into the fluid which the cavities 
contain. When the head is rotated in any plane, the 
contained fluid, in at least one of these canals, due to 
inertia, lags behind the walls of the cavity. Because 
of this, the projecting hair processes are bent to one 
side and the adjacent nerve fibres are stimulated. 
This action may be understood by thinking of a 
bucket filled with water into which projects moss 
that is attached to the wooden surface. When the 
bucket is rotated, the water lags behind and the 
moss is bent. If the bucket is kept twirling for a 
short time, the water takes up its motion and con- 
tinues to move when the bucket is stopped, thus 
reversing the direction of the moss. The semicircu- 
lar canals act in a similar way, so that when a person 
has been whirled for a time in a revolving chair and 
suddenly stopped, he responds as though he were 
being turned in the opposite direction. 

The adequate stimulus to these sense organs is 
rotary movement of the head. 

Static Organs. — On each side of the head adja- 
cent to the semicircular canals and contained in bony 
cavities are two small membranous sacs, the utricle 
and saccule. (See Figure 4.) Within them is a gel- 
atinous mass into which project sensory hair cells. 
Among the hairs are found small particles of cal- 
cium carbonate, called otoliths. The pressure of the 
otolith-weighted mass upon the hair cells varies with 
the position and movement of the head. 



THE ELEMENTS OF BEHAVIOR 23 

The adequate stimulus to these organs is the posi- 
tion of the head with reference to gravity, or motion 
of the head in any direction. 

Muscle and Tendon Sense Organs (Kinesthetic 
Organs). — In the muscles are found sensory " spin- 
dles' ' made up of modified muscle fibres and free 
nerve endings. Similar organs are found in the 
walls of blood vessels and in the tendons. 

The adequate stimulus for these organs is the me- 
chanical pressure and state of strain in muscles and 
tendons that results from any bodily movement. 

The Nervous System 

A stimulus starts a chain of neural events and a 
response terminates it. Between stimulus and re- 
sponse many things occur in the nervous system. 

The principle has already been stated that a re- 
sponse can not result from a stimulus unless there is 
a pathway of nervous conduction between receptor 
and effector. The whole nervous system is an intri- 
cate arrangement of such pathways. 

The brain is contained in the skull, and the spinal 
cord is contained in the vertebral column. The brain 
and spinal cord constitute the central nervous sys- 
tem. Sensory nerves lead from the sense organs to 
the spinal cord and brain. Motor nerves leave the 
brain and the spinal cord and lead to skeletal mus- 
cles. These sensory and motor nerves constitute 
the peripheral nervous system. In addition to the 



24 GENERAL PSYCHOLOGY 

central and peripheral nervous systems there is the 
autonomic nervous system. This system serves the 
involuntary muscles and the glands. The muscles 
that it affects are distinct in kind from the skeletal 
or voluntary muscles, being "unstriped" in appear- 
ance and slow in their action. Through the auto- 



SjoihaJ cord 




"Gland muscle 



Sf , {£/" or striped 
Inmiatay muscle 



Mmtari/ 

orstn 

muscl 



AUTONOMIC PERIPHERAL 

Figure 8. the relation op efferent fibres of the autonomic 

and the peripheral nervous systems to the central 

nervous system 

nomic system the central nervous system is con- 
nected with such effectors as sweat glands, salivary 
glands, tear glands, adrenal glands, liver, spleen, 
stomach, intestine, rectum, bladder, genitals, heart, 
and blood vessels. The autonomic has much the 
same function as the peripheral nervous system. 
The relation of the three systems may be se.en from 
Figure 8. 



THE ELEMENTS OF BEHAVIOR 25 

The Spinal Cord. — A cross section of the spinal 
cord shows an outer white area and an inner gray 
area whose shape varies at different levels of the 
cord but preserves a general resemblance to the let- 
ter H. (See Figure 9.) The outer white area is 
composed of longitudinal columns of nerve fibres en- 



Dorsal root 



Posterior 
horn 



interior 
horn 



Ventral 
root 

FlGUBE 9. SCHEMATIC SECTION OF THE SPINAL CORD. THE DOTTED 
AREA IN THE CENTER IS GRAY, DUE TO THE PRESENCE OF NERVE CELL 
BODIES AND UNMEDULLATED FIBRES. THE OUTER AREA IS MADE UP OF 
COLUMNS OF LONGITUDINAL FIBRES. AREAS OF MOTOR FIBRES ARE MARKED 
M., AND AREAS OF SENSORY FIBRES ARE MARKED S. OTHER 
AREAS ARE MAINLY CONNECTING FIBRES 



cased in their white medullary sheaths. The inner 
gray area is made up of two posterior (or dorsal) 
and two anterior (or ventral) horns with an isthmus 
of connecting or commisural fibres. Its gray ap- 
pearance is due to the presence of nerve cell bodies 
lacking the white medullary sheath that gives their 
color to the outer columns. 
The Brain. — The cerebral hemispheres constitute 



26 



GENERAL PSYCHOLOGY 



the largest part of the human brain. A cross section 
of one of these hemispheres shows an outer layer of 
gray matter that is called the cerebral cortex. This 

rermhol branches 
cf spinal cord 




FlGUBE 10. SCHEMATIC REPRESENTATION OF SENSOBY NEUBONE 

is made up of un-medullated cell bodies and nerve 
fibres. A large part of the interior ©f the brain is 
seen to be composed of white medullated tracts, al- 
though there are distributed in this area numerous 
patches of gray matter. 



THE ELEMENTS OF BEHAVIOR 



27 



Neural Arcs. — A sensory (or afferent) neurone 
starts at a sense organ and terminates in the spinal 
cord. Its branched processes, extending upward 
Dendrites 




Striated 

muscle 

fibers 

\ 



FlGUBE 11. SCHEMATIC BEPBESENTATION OF MOTOR NEUBONE 



and downward, form a part of the sensory columns 
of the cord, and from these columns its processes 
enter the dorsal horn at various levels. Connecting 
neurones, sometimes called association or internun- 
cial neurones, carry impulses from the sensory sys- 



28 GENERAL PSYCHOLOGY 

terns to motor systems. Every neural arc contains 
at least one such connecting neurone interposed be- 
tween its sensory neurone and its motor neurone. 
The cortex has many more of these connecting neu- 
rones than has the spinal cord, so that in the brain 
there are many intricate pathways, any one of which 
an impulse may follow, depending upon the varying 
resistance in the synapses encountered. Figure 12 
shows the relation of these connecting neurones to 
sensory and motor systems. 

The motor pathways in the central nervous sys- 
tem consist chiefly of pyramidal tracts running from 
the cortex to the anterior horn of the cord. From the 
anterior horn motor (or efferent) neurones lead to 
the muscles. 

When an impulse passes from a sense organ to a 
muscle by way of a sensory neurone, connecting neu- 
rones in the spinal cord and a motor neurone, its 
pathway is called a reflex arc,, (See Figure 12.) 
Such reflex arcs are usually instinctive mechanisms. 
A frog with its brain removed responds to many 
stimuli by means of these reflex arcs. 

Regulatory Character of Responses 

A significant characteristic of responses is that in 
general they meet successfully the situations that 
contribute the stimuli that call them forth. For ex- 
ample, a foreign object in the nose calls forth a 
sneeze response that removes the irritating object. 



THE ELEMENTS OF BEHAVIOR 



29 




Spinal cord 



Skin. 



Figure 12. scheme of neural pathways from a sense organ in 

the skin to a muscle. arrows indicate possible courses taken 

by a nervous impulse. the neurones are shown enlarged out 

of all proportion to the size of the brain 

and cord (after starr ) 



30 GENERAL PSYCHOLOGY 

The visual stimulus of a fleeing mouse causes the cat 
to make movements that result in the mouse's cap- 
ture, just as the mouse, receiving the visual stimu- 
lus of a cat, is impelled to make movements of flight. 
A baby will grasp the person who holds him if the 
support is suddenly released. One of the responses 
to* stumbling is extending the hands, and this pro- 
tects the more vital parts of the body from injury. 7 

A baby cries when he is hungry, cold, frightened, 
or in pain. This serves to bring his nurse to the 
spot. We might contrast this mutual regulation in 
human beings with the behavior of such a simple 
animal as the frog. Frogs never come to each other's 
rescue, even though they have pain and danger calls. 
The only call which summons the frog's fellow is the 
mating call. 

A familiar response of the dog is his scratching 
reflex. If stimulated with a pin point behind the 
right shoulder, the dog makes rapid oscillatory 
movements with the right hind leg, the utility of 
which movement is obvious. If the same stimula- 
tion be applied a short distance above the tail at a 
spot which the scratching foot cannot reach, the 
tongue makes reflex licking movements even though 
the dog does not attack the spot with his mouth. 
Thus stimulation of any part of the body brings into 
play regulatory responses that usually meet the sit- 
uation appropriately. 

The stimuli accepted by the distance receptors 

7 Smith, "Regulation in Behavior," Journal of Philosophy, 1914. 



THE ELEMENTS OF BEHAVIOR 31 

result in responses that adjust the animal to the 
good or evil that is about to befall it. In their 
simplest form these responses turn the animal 
toward or away from the stimulus, or increase or de- 
crease the distance separating object and animal. 

Delayed Utility of Responses 

The utility of a response is often not evident until 
a long time after it is given. The lapse of time oc- 
curring between the response and the advantage the 
animal reaps from it often makes the response seem 
a matter of prudent deliberation on the part of the 
animal, when this is really not the case. All re- 
sponses of lower animals are evoked by present sit- 
uations, even when the future situations to which 
they adjust the animal are far distant. This ad- 
justment to the future, in particular cases, may be 
fruitless, as the probable event may never transpire, 
but the response occurs regardless of this uncer- 
tainty. These probable events are the situations in 
the environment of the species that recur periodi- 
cally, such as night, or high tide, or winter, or new 
laid eggs. The brooding hen does not foresee the 
consequences of her act, but is merely responding 
to the eggs, the nest, and the physiological changes 
in her own body. The situation that causes the 
squirrel to store food in October is not the inevitable 
scarcity of nuts during the following winter, but 
rather the surplus food supply in the autumn. Some 



32 GENERAL PSYCHOLOGY 

anticipatory reactions of animals are of use only to 
others, and an animal often dies before the utility 
of his act is manifest. A conspicuous example of 
this is the behavior of the solitary wasp in catching 
and storing food for an offspring whose birth she 
does not ordinarily survive. 

The biological utility of the mating and nest build- 
ing of birds is the birth and shelter of the offspring. 
The bird, however, responds to the situation at the 
time with as little regard for the future as man has 
when he coughs or sneezes in response to foreign 
objects in the throat and nose. 

Appakent Absence of Utility of Some Eesponses 

Although we may usually expect to find some use 
served by every response, there are many cases of 
inappropriate reactions. For example, the instinct 
that leads a dog to run barking beside the front 
wheels of an automobile seems to serve no useful 
purpose either to dog or driver. If we remember, 
however, that the dog is the descendant of the wolf 
and that the wolf in killing his prey must depend 
upon the pack for assistance, it is clear that there 
was a time when this reaction was of service. By 
these movements that are so annoying to us in the 
dog, the single wolf, fleeter than his fellows, over- 
takes and turns back his prey so that the whole pack 
take part in the killing. The absence of utility in 
the dog's act is due only to the fact that he lives in 



THE ELEMENTS OF BEHAVIOR 33 

artificial conditions. Many of man's inappropriate 
responses that are spoken of as immoral have, at 
some period in the history of the race, been a neces- 
sary means to his survival. 

Living in a complex civilization makes many of 
our original reaction tendencies inappropriate. Our 
proneness to anger toward telephone operators, or 
toward the automobile that resists our efforts to 
start it, is often of no use to us. Our natural equip- 
ment does not include appropriate responses to these 
situations. Loudness of voice and violent action 
are the innate responses to situations not wholly dis- 
similar to an irritating operator or to a recalcitrant 
machine, so these are the responses given by the un- 
regenerate. When a man steps in front of us in the 
line waiting for theater tickets, our adrenal re- 
sponse, promoting as it does the clotting of the 
blood, prepares us for actual bloodshed, although 
this is usually needless as we may never come to 
blows. 

Orientation, Locomotion, and Intervention 

A response to stimulation is often a turning 
toward or away from certain objects. These objects 
are usually themselves the source of the stimulus 
that causes the turning. The altered position gen- 
erally serves one of two purposes. It may put the 
animal in a position to employ mouth or legs to ad- 
vantage, as when a startled animal takes up an atti- 



34 GENERAL PSYCHOLOGY 

tude of defense or prepares for flight. It may 
change the direction of the animal *s sense organs 
with reference to the provoking stimulus or with 
reference to other stimuli usually associated with 
this. For example, the horse cocks his ear toward 
the unusual sound, thus bringing the sense organ 
further into play. The herd wheel in the direction 
from which danger may be expected in response to 
the danger cry of the leader. Taking up a posture 
that permits the appropriate action of receptors or 
effectors, or that withdraws receptors from stimu- 
lation, is called orientation. 

Many of an animal 's movements, such as walking, 
running, jumping, swimming, crawling, or flying, 
serve to impel him from place to place. Movements 
that cause a change of location of the animal as a 
whole are called locomotion. 

Responses of orientation and locomotion fre- 
quently occur simultaneously. If a cow is standing 
by the roadside facing us as we approach in a vehi- 
cle, she merely maintains her orientation with re- 
spect to the vehicle, by slowly turning her head as 
we pass. If, on the other hand, we approach her on 
the flank, her head turns toward the road in response 
to the sound, but she is also actuated to flight. In 
order to keep her eye on the vehicle and at the same 
time to move forward, she wheels slowly and crosses 
the road ahead of us. What seems to be a mere per- 
versity in the cow is explained as a combination of 
these two action systems. 



THE ELEMENTS OF BEHAVIOR 35 

Orientation and locomotion change the position 
of the animal with reference to objects in the en- 
vironment, but do not change the position of sur- 
rounding objects with reference to each other. Re- 
sponses that serve to redistribute the parts of the 
outside world will be called intervention. Respon- 
ses of intervention, as, for example, picking up an 
object, always involve orientation, and often loco- 
motion as well. 

Movements of orientation, locomotion, and inter- 
vention all serve to bring new stimuli to bear on 
the animal and these in turn are succeeded by new 
responses. The proportion of intervention respon- 
ses in higher animals is strikingly greater than in 
lower forms. In response to variations of season 
and food supply, birds employ orientation and loco- 
motion, thereby bettering their environment. The 
hermit crab travels about until he finds a shell that 
affords him shelter. Man, on the other hand, by 
means of his elaborate intervention responses, so 
constructs the world about him as to lessen his de- 
pendence upon movements of orientation and loco- 
motion, with a resulting increase of convenience and 
safety. He plants his crops and breeds his cattle 
instead of searching for wild vegetables or game. 
He is born naked and assumes or discards clothing 
according to the weather. He brings together into 
one place shelter, clothing, bed, food, water, fuel, 
utensils, mate, and offspring. From his immediate 
neighborhood he removes dirt, enemies, and danger- 



36 GENERAL PSYCHOLOGY 

ous objects. He constructs tools and weapons that 
are of assistance to him in further movements of in- 
tervention. By an elaboration of mechanical con- 
trivances he devises vehicles that take the place of 
his legs in locomotion, and instruments" that extend 
the range and accuracy of his sense organs. 

Internal Responses 

The three types of responses just mentioned, ori- 
entation, locomotion, and intervention consist in 
movements of the skeletal muscles. Animals re- 
spond also by movements of visceral muscles and by 
glandular secretion. 8 The dog that smells appetiz- 
ing food not only turns toward the food, approaches 
and tears it with his teeth, but also responds by cer- 
tain internal reactions of peristalsis and secretion. 
Peristalsis is a wave-like muscular constriction of 
the enteric tract that serves to carry food, once 
taken into the mouth, into stomach and intestines, 
and to knead the food in such a way that all parts of 
it are brought into contact with the secreting and 
absorbing walls. Secretions into the enteric tract 
serve to prepare the food for absorption. The prin- 
cipal glands that serve digestion are in the mouth, 
stomach, intestines, pancreas, and liver. At the 
sight or smell of food, the mouth and stomach are 
prepared by their secretions to receive it. The flow 
of these secretions is later increased by the presence 

s For a detailed account of such internal responses see Cannon, 
Bodily Changes in Pain, Hunger, Fear, and Rage. 



THE ELEMENTS OF BEHAVIOR 37 

of food in the mouth, by the movements of chewing, 
and by the peristalsis of which swallowing is a part. 

When a cat is enraged by a barking dog, it not only 
"spits" and assumes the posture of defense, but its 
peristalsis ceases, and the blood vessels so change 
their size, by the play of minute muscles in the ves- 
sel walls, that a greater blood stream reaches the 
fighting and fleeing groups of skeletal muscles. 
Sugar stored in the liver is liberated. From the 
adrenal glands adrenin is secreted and poured into 
the blood, with the result that fatigue is counteracted 
and the vasomotor condition and absence of peris- 
talsis are maintained. Heart beat and respiration 
show an appropriate increase of amplitude and rate. 
As a rule, internal responses do not occur alone, but 
accompany movements of orientation, locomotion, 
and intervention. They facilitate these movements 
and, in turn, are further excited by them.. 

Emotional expression is made up of overt bodily 
movements and of characteristic internal responses 
accompanying them. The grouping of responses in 
each emotion shows great resistance to the rear- 
ranging effects of training, as is indicated by their 
fundamental similarity in diverse races. Grief, 
merriment, anger, and love are expressed in much 
the same way the world over. They are aroused, 
however, by varying situations in different socie- 
ties. 9 



9 See Darwin, The Expression of the Emotions in Man and in Ani- 
mals, pp. 83-115. 



38 GENERAL PSYCHOLOGY 

When a person is stirred to action by the internal 
responses of rage, fear, or love, we say he is 
1 ' moved.' ' This is more than a mere figure of 
speech. A situation that hampers movement causes 
the response of struggling with head, body, arms, 
and legs, but it also, either directly or because of the 
struggling, causes certain internal responses like 
those described in the case of the enraged cat. These 
internal responses stimulate proprioceptors in the 
viscera. The impulses so aroused are conveyed 
along neural arcs to the muscles engaged in strug- 
gling, and the action of these muscles is thereby 
strengthened and sustained. If the pathways of ner- 
vous conduction between proprioceptors and skele- 
tal muscles should be severed, this reenforcement 
would not take place and the struggling movements 
would be less energetic and shorter-lived. 

The secretion into the blood of adrenin from the 
adrenal glands reduces the peristaltic movements 
in the intestinal tract, increases by its action upon 
blood vessels the amount of blood in the skeletal 
muscles, and, by direct contact, makes more ener- 
getic the contraction of the skeletal muscles involved 
in the expression of rage. It probably promotes 
clotting of the blood, which is of advantage in case 
the ensuing fight results in the animal's being 
wounded. 

This action of adrenin is another way of eliciting a 
response. Between the gland and the muscles acted 
upon there is no nervous connection. The blood 






THE ELEMENTS OF BEHAVIOR 39 

stream carries the gland's secretion to the muscles, 
and the secretion has a direct chemical action upon 
the muscle tissue. Thus the direct action of internal 
secretions from ductless glands is complementary 
to the conduction of impulses from visceral pro- 
prioceptors through neural arcs. The effect of these 
secretions is less prompt than is the effect of neural 
reenforeement, but persists for a longer time. 

The Action of a Stimulus-Response Mechanism 

Many weak stimuli, which act upon sense organs 
without causing a response, will be found to call 
forth a response when the stimuli are increased in 
intensity. A stimulus of an intensity just sufficient 
to bring about a reaction is called a threshold stimu- 
lus or liminal stimulus. This is not to be confused 
with the term " adequate stimulus,' ' which denotes 
the kind or class of stimuli ordinarily capable of 
exciting a sense organ. We may give a baby a qui- 
nine solution so weak that he will swallow it as 
though it were pure water. If the strength of the 
solution is gradually increased, we reach a point at 
which the baby will grimace and turn his head away. 
This constitutes the threshold point. 

If, instead of increasing in intensity a stimulus 
that is less intense than the threshold stimulus, we 
repeat such a stimulus again and again, a response 
may be elicited. Bringing about a response by the 
repetition of a subliminal stimulus is called the sum- 



40 GENEKAL PSYCHOLOGY 

mation of stimuli. If, for example, a neighbor 
comes at night and persistently knocks on a man's 
door, the man finally rises from bed and lets him in, 
not because it is more reasonable to do so now than 
it was when the knocking began, but because of the 
neighbor's importunity. 

The summation of stimuli is used extensively in 
advertising, the recurring advertisement often lead- 
ing us eventually to buy the article described. This 
accounts in part for the number of people who use 
Ivory Soap and Bull Durham. The daily sight of 
the unanswered letter in the letter tray may finally 
call forth a reply. The ingenious torture that con- 
sisted in allowing a series of drops of water to fall 
on the bound victim produced a summation effect 
resulting in a greatly increased response. 

Within certain limits the summation effect is in- 
creased as the length of the intervals between the 
subliminal stimuli is diminished. If the intervals 
are lengthened beyond a certain point, no summation 
effect occurs. 

A response is sometimes given only after a num- 
ber of diverse subliminal stimuli have been received, 
and may be the result not only of the last stimulus 
but of the entire series. Bringing about a response 
by a series of diverse subliminal stimuli is called 
the summation of diverse stimuli. The prospective 
purchaser of an automobile is led to visit the sales- 
room but remains irresolute in the presence of the 
machine. The salesman now initiates the process of 



THE ELEMENTS OF BEHAVIOR 41 

summation. He calls the man's attention to various 
good features of the machine, and each of these 
stimuli brings the man nearer to parting with his 
money. The salesman appeals to his customer's 
vanity by reference to prominent men who own that 
make of machine. Finally a stimulus is given, such 
as the assurance that after this car is sold none will 
be available for several months, and the purchaser 
makes out his check. 

To induce a child to take medicine, the summation 
of diverse stimuli is often effective. If a promise of 
candy or of money does not have results, we may 
try such bribery as offering to take him to the thea- 
ter, or we may threaten to leave him at home. 
Finally, by petting or cajolery, the summation is 
completed. We often describe a person as being 
favorably disposed toward a certain course of action. 
This usually means that he has already received the 
first few of a series of diverse stimuli and all that we 
need do is to complete the series in order to bring 
about the response. For example, a man's child 
may have died recently and we realize that the time 
is auspicious for asking him to contribute to a chil- 
dren's charity. The acquaintance whom we would 
greet casually at home is welcomed effusively in a 
foreign country because we are already stimulated 
to friendliness by the internal changes that in part 
constitute homesickness. 

The response to a series of stimuli varies accord- 
ing to the order in which the stimuli occur. A man 



42 GENERAL PSYCHOLOGY 

standing beside a dark road responds differently to 
the sounds of approaching footsteps and to the 
sounds of retreating footsteps, which may be exactly 
the same sounds occurring in opposite order. 
Royce pointed out that it makes a difference 
whether a stranger first steps on a man's foot and 
then apologizes, or first apologizes and then steps 
on a man's foot. 

Webee's Law 

Within certain limits the intensity of a stimulus 
may vary without modifying the nature of the re- 
sponse. If the stimulus is increased or decreased 
beyond these limits, the response alters its charac- 
ter or its energy. The amount by which a stimulus 
must be increased or decreased in intensity in order 
to alter the response is called the differential thresh- 
old. This term should not be confused with liminal 
threshold. 

About 1825 it was suggested by Weber, a German 
investigator, that the ratio of the differential thresh- 
old to the amount of the stimulus is constant at all 
intensities for each class of stimuli. 10 Although the 
law does not hold for very weak or for very intense 
stimuli, it has proven a demonstrable and valuable 
generalization. The ratio differs with different 
kinds of stimulation, being, for example, smaller 
in the case of light than in that of sound. 

10 For a more detailed account of Weber's Law see Ladd and 
Woodworth, op. cit., pp. 361ff and 374ff. 



THE ELEMENTS OF BEHAVIOR 43 

The reflected light from a candle introduced into 
a sunlit room may not be noticed, but such an in- 
crease of illumination in twilight is at once appar- 
ent. It may be impossible to distinguish between a 
pitch of 512 vibrations and one of 513, but easy to 
hear the difference between pitches of 32 and 33 
vibrations. A weight of 80 grams and one of 82 
grams may be reported as being the same, but a 
weight of 20 grams and one of 22 will probably be 
recognized as different. It is evident that the ap- 
parent difference between two lights does not de- 
pend so much upon the absolute difference between 
the stimuli as upon the proportion of this differ- 
ence to the intensity of the light. An absolute dif- 
ference between two sound intensities does not in- 
sure our distinguishing between the two, for if the 
intensities are great this difference may be inade- 
quate. The same is true of two weights, which stim- 
ulate us to different responses only if one is about 
three per cent heavier than the other. The just 
noticeable difference for light is about one per cent 
of the intensity of the stimuli. These differential 
thresholds vary greatly with different subjects and 
hold only within a limited range of intensities. 

or 

The Interaction of Stimulus-Besponse Mechanisms 

As no animal is ever acted upon by just one stimu- 
lus at a time, but at any given moment is exposed 
to a great complexity of stimuli, its resulting be- 



44 GENERAL PSYCHOLOGY 

havior is the interplay of many responses. The ac- 
tion of any stimulus depends on the other stimuli 
that occur along with it. A loud sound heard on 
the city streets causes a response different from 
that given to the same sound when the hearer is 
alone in the woods. 

The combination of all the stimuli to which an ani- 
mal responds at any moment is called a situation, 
and a combination of responses is called an act. 11 

If the situation that confronts the animal tends to 
arouse simultaneously two stimulus-response mech- 
anisms, there may occur one of two results. One 
of the mechanisms, though not itself responding, may 
increase the tendency of the other to respond; or 
one may interfere with the action of the other. 

The first of these results, where one system is an 
aid to the other, is called facilitation. This aid or 
reenforcement produces a more lively response in 
the system that is facilitated. Suppose a man, see- 
ing a bear in the woods, responds by a dignified re- 
treat. The bear now moves in the man's direction 
and he, previously walking, breaks into a run. Pigs 
eat more greedily when other pigs are sharing the 
meal, and almost any animal will partake more rap- 
idly of the food that we threaten to remove. A 
toothache ends our delay in visiting the dentist, and 
a good appetite makes us respond promptly when 
summoned to dinner. 



11 These definitions are proposed by Watson, Psychology from the 
Standpoint of a Behaviorist, p. 10. 



THE ELEMENTS OF BEHAVIOR 45 

An increased tendency to act is to be expected 
when two stimuli lead to the same response, but 
this increased tendency may also occur in cases 
where the responses produced by the two stimuli 
are not the same. 

The difference between facilitation and the sum- 
mation of stimuli lies in this, that the stimuli com- 
bined in summation are all subliminal and occur 
serially, whereas the stimuli combined in facilitation 
may or may not be subliminal and if subliminal must 
occur simultaneously. 

Contrasted with facilitation is the case of inter- 
ference between two stimulus-response mechanisms. 
As a result of interference three things may hap- 
pen; either both responses are given with lessened 
energy, or one response is given with lessened en- 
ergy and the other is not given, or neither response 
occurs. The hampering effect that one system has 
upon another is called distraction. The preventing 
effect that, one system has upon another is called 
inhibition. If a trap is baited and an animal is led 
by the odor of the bait to approach the trap, and if 
there is no odor of man about the trap, the animal 
will seize the bait and be caught. If, however, the 
body odor of the trapper adheres to the trap, the 
animal will either take the bait less readily or will 
entirely disregard it. If the bait is taken reluctantly, 
the body odor is a distracting stimulus ; and if it is 
not taken at all, the body odor is an inhibiting 
stimulus. 



46 GENERAL PSYCHOLOGY 

The reason one response prevails over the other is 
either that there is more resistance in the conduc- 
tion path of one system than in that of the other, 
or that the relative strength of the two stimuli in 
terms of their thresholds is different. 12 

When interference so raises the threshold of both 
responses that neither is given, we have mutual in- 
hibition. In this case a third stimulus may bring 
about a response that removes the animal from the 
first two stimuli, and the interference disappears. 
This may be seen in the case of a man who is ad- 
dressed by someone while he is reading. He pauses 
in his reading and it is now doubtful whether he will 
answer the questioner or resume his book. One of 
these responses will eventually be given unless a 
third stimulus, such as the ringing of the telephone, 
causes him to disregard both book and questioner. 
Ordinarily man is acted upon not by two but by a 
multiplicity of stimuli, and his responses are de- 
termined by facilitating stimuli, inhibiting stimuli, 
distracting stimuli, and by the stimuli that primar- 
ily elicit the response. 

Compeomise Responses 

When a spinal dog is simultaneously stimulated 
at a point on the shoulder and at a point several 
inches farther back, he scratches a spot somewhere 

12 For a discussion of the neural basis of interference, see Sher- 
rington, op. tit., pp. 55, 115-149, 223. 



THE ELEMENTS OF BEHAVIOR 47 

between the two. His response is in the nature of 
a compromise. Man, as well, when stimulated to 
two distinct responses, often acts in a way that is 
a resultant of the two response tendencies. When 
playing ball with a stone, we tend to throw it as if 
it were a ball to the person who is about to catch it, 
and we tend to refrain from throwing it because 
we are in the habit of not stoning our friends. The 
resultant act consists in throwing the rock gently. 

Compromise in emotional responses is the rule 
rather than the exception. If a child's mischief an- 
noys us, we respond to him both as to a child to be 
treated kindly and as to a nuisance to be abated. 
The resultant response is remonstrance with sad 
good humor. When a puppy is scolded, his behavior 
is a compromise between affection and fear, and is 
somewhat suggestive of the politeness of human 
beings in the presence of strangers. 



CHAPTER II 



INSTINCT 



If we know the structure of a machine, we can 
predict what it will do whenever it is acted upon 
in a familiar way. Man is no exception to the rule, 
and we find that in so far as men are alike in struc- 
ture they respond in the same way whenever their 
sense organs are acted upon in a like manner. 
Babies all show a great similarity of structure at 
birth before they begin to learn, and, to a consid- 
erable extent, this similarity of structure persists 
when they become adults, and even after each has 
taken on individual peculiarities due to the particu- 
lar influences to which he has been exposed. 

In addition to this partial persistence of the baby's 
original nature, there is a closely related factor that 
helps to make all men somewhat alike. This is that 
the structures of all of us tend to change in the 
same way as we grow older. This change we call 
maturation. 

Acts that are due to original structure, or due to 
a structure resulting from simple maturation, we 
call instincts. Such a definition as this makes it pos- 
sible to describe all behavior as either instinctive or 
learned. 

48 



INSTINCT 49 

Reflexes 

Spinal reflexes have been described in Chapter I. 
Man's original structure includes most spinal reflex 
arcs, and, in addition to these, many neural arcs of 
greater complexity whose pathways involve connect- 
ing fibres in the medulla and brain. All these natural 
pathways through the brain are usually called re- 
flex arcs of higher level. The fixation of a light 
that has fallen on the periphery of the retina, and 
the grimacing due to a bitter substance on the tongue 
are examples of such higher level reflexes. 

A baby that is just born is almost wholly lacking 
in experience. Although for some time before birth 
the sense organs, the nervous system, and the 
muscles are sufficiently mature to function, a con- 
clusion that is proved by the behavior of premature 
infants, the child's isolation and confinement pre- 
vent any very elaborate responses. 

At birth the infant enters a world rich in situa- 
tions, and a world permitting freedom of movement. 
Then for the first time he experiences light, odor, 
temperature, and cutaneous pain stimuli. He then 
draws his first breath, cries, swallows, coughs, 
sneezes, nurses, and fixates objects with his eyes. He 
is still a creature of reflexes, although some of these 
reflexes, such as the movements of nursing, occur in 
fairly predictable series. 

Many careful observations and experiments have 
been made upon babies from birth in order to dis- 



50 GENERAL PSYCHOLOGY 

cover the nature of their reflex responses. 1 The 
maternity hospital affords excellent opportunity for 
this work during the first few weeks of the baby's 
life. Movements made by an infant at birth may be 
regarded as natural tendencies unaffected by habit 
formation. In the case of responses made after a 
baby is several weeks old, even though they are then 
performed for the first time, there is always a pos- 
sibility that they are a product of training, although 
often it seems more plausible to regard them as 
natural tendencies that are the outcome of simple 
maturation. The ability of a baby to reach out and 
grasp an object that he sees, usually appears when 
he is four or five months old. It is uncertain 
whether this act is due wholly to the maturation of 
his nervous system or is the result of trial and 
error learning. Before this so-called eye-hand co- 
ordination is attained, he has grasped many objects 
that come in contact with the palm of his hand and 
has fixated these objects with his eyes. "Whether 
or not this act is instinctive could be decided only 
by placing the child in such restraint that no experi- 
ence in casual grasping would be possible. If, on 
being given his freedom at the proper time, the 
eye-hand coordination at once occurred, we could 
assign it with certainty to the category of reflex. 
The suddenness with which this and other coordi- 
nated movements appear, however, lends plausibility 

i Watson, Psychology from the Standpoint of a Behaviorist, chap. 
6 and 7. 



INSTINCT 51 

to the assumption that such acts are dependent upon 
late maturation and are to some extent independent 
of training. 

Just after a baby is born, and when he begins to 
breathe, a vocalization known as the birth cry occurs. 
This cry is elicited by asphyxia and the customary 
slapping. Yawning has been observed five minutes 
after birth, and sneezing sometimes occurs as soon 
aa the baby is born. Blanton 2 describes the " colic 
cry" as being high pitched and different in this 
respect from the general crying due to hunger, pain, 
and fatigue. Crying in response to a cold plunge 
may be inspiratory in character. Drawing down 
the corners of the mouth while crying has been ob- 
served 30 minutes after delivery, and the trans- 
verse crease between the eyes may occur at birth. 
Being picked up may cause the baby to cry, and a 
surgical operation will at any time cause this re- 
sponse. 

Blanton reports the following sounds during the 
first month : m, n, ng, h, w, r, y, ow as in owl, ee as in 
feel, oo as in pool, a as in an, and a as in father. 

The enteric responses given the first day are swal- 
lowing, hiccoughing, regurgitation, spitting out, 
sucking, licking, and defecation. 

Binocular accommodation and fixation of a light 
are often to be observed during the first hour. Fixa- 
tion is most easily elicited when the light is placed 

2 Blanton, "Behavior of the Human Infant," Psychological Review, 
1917, pp. 456-483. 



52 GENERAL PSYCHOLOGY 

directly in front of the child. Blanton reports that 
the eyes of many babies follow a slow moving hand 
at birth. "Watson observed no blinking in response 
to a threatening gesture prior to the fifty-fifth day. 
The head may be rotated toward the source of light 
during the first few days. Tears may be present 
from birth. 

Smiling has been observed in babies as young as 
four days old and may result from tickling on the 
face, stroking other parts of the body, rocking, or be- 
ing turned on the abdomen across the nurse's knee. 

In response to sound, the child may start, squirm, 
cry, or awaken from sleep any time after birth. 

If placed face down upon a flat surface, the baby 
may rotate the head a half hour after birth. Ac- 
cording to Blanton practically all babies three days 
of age will raise the head when the face is buried in 
a pillow. When held in a sitting posture, the baby 
may hold its head in equilibrium after the second 
or third day. 

Finger movements may be observed at birth, and 
the grasping reflex is sufficiently strong from this 
time on to make it possible for the infant to sup- 
port its body weight when holding to a rod. This 
muscular contraction is due to cutaneous stimulation 
of the palms, and to stretching of the tendons. The 
response is most energetic in the case of a crying 
child. 

At any time after birth, when the child is dropped, 
the arms are thrown up toward the head. When the 



INSTINCT 53 

head is being scrubbed shortly after birth, the in- 
terference of the baby's hand sometimes interrupts 
the process. Watson, on taking hold of the nose of 
a three-day old baby, found that the child's hands 
almost immediately engaged his fingers. Avoidance 
movements of the arms may be elicited in very young 
infants by gentle pricking of the wrist. Kicking is 
commonly aroused by the clamping and tying of the 
umbilical cord. 

Blanton found that dropping alcohol on either side 
of the abdomen elicited a leg movement on the side 
stimulated. She reports that when the big toe is 
pricked to secure a specimen of blood, the other foot 
is drawn up and pressed against the ankle of the 
pricked side. Watson found that when an infant at 
five days of age is pinched on the inner surface of the 
knee, the other heel will be brought up to this spot. 

Stretching and arching in response to removal of 
clothing has been observed on the twenty-fifth day. 
Shivering may occur shortly after birth and the toes 
may be curled when the feet are exposed to the 
warmth of a fire when the child is a few days old. 

If a baby is suddenly lowered, in addition to the 
upward movement of the arms, there is elicited 
grasping and holding the breath. Another coordi- 
nated movement that may occur during the first few 
days is turning over after being placed face down. 
Creeping backward may occur during the second 
week, but the change of position is very slight. Blan- 
ton records in the case of one baby two hours old the 



54 GENERAL PSYCHOLOGY 

repeated act of placing the hand in the mouth. The 
youth of the child would indicate this to be an in- 
stinctive mechanism. 

Watson found no tendency on the part of a baby 
of 169 days to wipe its hands when given a ball of 
library paste. If hand wiping is an instinct, which 
may be doubted, it matures at a later period. The 
same experimenter could elicit no swimming move- 
ments from young infants, which contradicts the 
accounts of the recapitulationists. 

Some of Watson's observations of emotional re- 
sponses may be stated here. Blinking and an up- 
ward movement of the hands were elicited at 100 
days in response to a threatening gesture. Crying 
followed loud sounds or the jerking of the baby's 
blanket. No fear responses were given by the 165- 
day old baby to the sight or handling of a cat, a rab- 
bit, or a pigeon. Rage responses, consisting of 
stiffening the body, holding the breath, thrashing 
with arms and legs, and screaming, were produced 
by hampering the infant's movements or by simply 
holding the arms or head. 

Instincts aee Chain Reflexes 

No response is ever given that does not in turn 
cause the stimulation of some sense organ. The con- 
traction of a muscle stimulates the muscle spindles 
that are contained in it. The secretion of saliva or 
tears stimulates adjacent touch organs. Vocaliza- 



INSTINCT 55 

tion stimulates the ear of the person who makes the 
sound as well as the proprioceptors in the contract- 
ing muscles. Scratching, clenching the fist, sneez- 
ing, winking, swallowing, breathing, or a response 
of any sort whatever, produces its characteristic 
stimulus. Stimuli furnished by responses are called 
movement-produced stimuli. 

Many responses cause new stimuli from the ex- 
ternal world to act upon us. If we open our eyes, 
turn our head, touch the stove, walk from place to 
place, open a book, light a cigar, or call to a passer- 
by, the act itself is productive of new stimuli. These 
stimuli from the external world that result from re- 
sponses are also called movement-produced stimuli. 

Movement-produced stimuli in their turn result in 
movements, and these movements cause further stim- 
ulation. In this way a chain of reflexes once begun 
may maintain itself by its own movement-produced 
stimuli. When the chain of stimuli are within the 
body, the order of the responses is highly predict- 
able. This is because the structure of the body is 
fairly stable. A person who begins to yawn always 
finishes because the muscle strain of the first part 
of the act causes the movements that complete the 
series. No one stops with an open mouth and fails 
to finish his yawn. (See Figure 13.) 

When movements bring stimuli from the external 
world to bear upon us, the chain of reflexes that re- 
sults is predictable if the external situation is famil- 
iar and common. Man is strikingly adjusted to 



56 GENEEAL PSYCHOLOGY 

any of these commonly recurring situations in that 
his responses cause changes in the external world 
necessary to his preservation. 

Suckling is a chain of reflexes, each reflex being 
called out by the stimulus that the preceding re- 
sponse produces. If a baby is gently tickled on the 
side of the mouth or on the cheek, its head is moved 
so as to engage the stimulating object with its mouth. 




FlGUEE 13. DIAGRAMMATIC REPRESENTATION OF THE CHAIN REFLEX 
MECHANISM (AFTER HERRICK). C, SYNAPSES IN NERVE CENTERS. 
E, EFFECTORS. R, RECEPTORS. THE ACTION OF EACH EFFECTOR RESULTS 
IN THE STIMULATION OF AN ADJACENT RECEPTOR. THE STIMULATION 
OF EACH RECEPTOR RESULTS IN THE* ACTION 
OF AN EFFECTOR 



This is a reflex. In finding the breast the baby is 
thus guided by the erectile mamilla. The mamilla 
in his mouth is the stimulus to reflex movements of 
the neck, jaws, tongue, and lips that cause close con- 
tact with the breast and produce suction. These 
movements result in milk's entering the mouth. 
When milk is taken into the mouth, it is the stimulus 
to reflex swallowing. 

It will be seen that each step in the series of nurs- 
ing movements is an act of intervention that brings 
about the stimulus for the next movement. Each 
step may, however, be elicited independently by the 
proper stimulus. Any touch on the cheek may cause 



INSTINCT 57 

the mouth to engage the stimulating object. Any- 
thing placed between the lips may cause reflex suck- 
ing. Any fluid in the mouth may cause swallowing. 
That these acts are called forth in the proper series 
depends upon the presence of a nursing mother. 
She is the ubiquitous situation to which all babies are 
adjusted. 

If movement-produced stimuli alone caused the 
baby's next reaction, he would lose his way in the 
world and perish. Fortunately, however, he is 
guided by a world of orderly events. Conversely, 
if the baby had no original organization to deter- 
mine in part the sequence of reactions, the baby, by 
trial and error learning, would have to establish 
the order of the minute parts of all the serial re- 
sponses necessary for his survival from birth. 
Otherwise he could live only in situations that would 
call out in the proper order the parts of each re- 
sponse. That one response may lead to another with- 
out learning, and guided chiefly by movement-pro- 
duced stimuli, is well illustrated in some of the co- 
ordinated movements of newborn animals. 

The baby's endowment consists of relatively sim- 
ple mechanisms, with fewer instinctive responses to 
movement-produced stimuli than are found in most 
of the lower animals. Compared with the wasp, 
which flies, stings, and secures its own food from 
the time it leaves its cell, the baby has much to learn. 
It is here that the child's capacity for learning com- 
pensates for his early helplessness, and secures for 



58 GENERAL PSYCHOLOGY 

him in the end an integration of behavior much more 
elaborate than that of an insect. The number as 
well as the simplicity of the responses that are ready 
to be attached to the child's private environment and 
to the stimuli that his own movements provide, con- 
tributes to this ultimate superiority. 

Whereas the lower animals, in response to any 
one of a number of stimuli, make the same elabo- 
rately coordinated movement involving many effec- 
tors, the baby responds to each stimulus with a sim- 
pler bodily movement, but with a movement more 
particularly reserved for that element of the situa- 
tion. In this way the behavior of the human infant 
exhibits frequent incongruities and combinations of 
reaction that interfere with one another. Gradually 
his responses are coordinated and adjusted to his 
world in a fashion that will be described under the 
heading Shortening of a Trial and Error Series. 

Thus the instincts of babies are more numerous 
and less complex than are the instincts of the young 
of other species. Human beings are not endowed 
with ready- formed tendencies to fight, hunt, swim, or 
build shelter. These elaborate instincts in lower 
animals are due to many definite reflex responses to 
movement-produced stimuli. All such acts in man 
are learned. Even putting out the hand and grasp- 
ing an object may be an art acquired by trial and 
error. Suckling and the emotional responses are the 
most elaborate of man's instinctive chain reflexes. 
The movements involved in these acts are stereo- 



INSTINCT 59 

typed in order and in kind, and these action patterns 
maintain in large part their integrity throughout 
life. 

Mr. and Mrs. Peckham have described an interest- 
ing chain reflex (instinct) of a solitary wasp, as fol- 
lows : 3 

She worked for an hour, first filling the neck of the 
burrow with fine earth which was jammed down with 
much energy — this part of the work being accompanied 
by a loud and cheerful (sic) humming — and next arrang- 
ing the surface of the ground with scrupulous care, and 
sweeping every particle of dust to a distance. Even then 
she was not satisfied, but went scampering around, hunting 
for some fitting object to crown the whole. First she tried 
to drag a withered leaf to the spot, but the long stem stuck 
in the ground and embarrassed her. Relinquishing this, 
she ran along a branch of the plant under which she was 
working and, leaning over, picked up from the ground 
below a good-sized stone ; but the effort was too much for 
her, and she turned a somersault on to the ground. She 
then started to bring a large lump of earth; but this evi- 
dently did not come up to her ideal, for she dropped it 
after a moment, and seizing another dry leaf carried it 
successfully to the spot and placed it directly over the nest. 

An important fact in the behavior of any animal 
is that it persists in what it is doing up to a certain 
point and then turns to something else. The wasp 
responds to the various small objects in the neigh- 
borhood by attempting to drag them to the hole, 

s G. W. and E. G. Peckham, Wasps, Social and Solitary, Boston, 
1905. 



60 GENERAL PSYCHOLOGY 

and then desists when the hole is covered. The baby 
responds by well established reflexes to objects touch- 
ing his cheek, to -anything inserted between his lips, 
and to fluid in his mouth, until his hunger is dis- 
sipated. In these cases, covering the hole and fill- 
ing the stomach are called consummatory responses. 
Although reflexes may be classified according to 
the stimuli that call them forth, or according to the 
responses that result, such a classification is impos- 
sible when we deal with an instinct that is a chain of 
reflexes. This is because the chain of reflexes does 
not always follow a fixed order, excepting in that 
it is terminated by a characteristic response. It is 
in terms of these final responses that instincts are 
classified. 

Pkecurrent and Consummatory Responses 

When we attempt to describe what an animal is 
doing, we find that we can distinguish between cer- 
tain responses that mark the end of a series of acts 
and those that lead up to this final response. We 
may see a dog running about in a field, occasionally 
picking up a scent and following it, losing the scent, 
ranging about until it is recovered, and barking, all 
with evident excitement. We explain his behavior 
by saying that he is after a rabbit, although it is evi- 
dent that the rabbit itself is not acting as a visual 
stimulus. One of the important stimuli for the dog's 
activity is the scent the rabbit leaves behind it. The 



INSTINCT 61 

odor prompts the dog to follow the trail with his 
nose to the ground, and arouses energetic emotional 
responses. A part of the movements that would be 
involved in seizing the rabbit are also present, but 
the act of seizing can not be entirely carried out be- 
cause there is no rabbit near enough to be seized. 
That the stimuli that cause the dog to hunt are in 
part internal stimuli, is shown by the fact that this 
behavior appears whenever the dog has been for a 
time without food. 

The response that puts an end to this activity is 
killing and devouring the rabbit. The reason that 
the activity ends is that the internal stimuli that 
prompted the animal to range about have been re- 
moved by the act of eating. 

Many responses are of such a nature that they 
bring to an end the stimuli that caused them. Often, 
when a response is prevented, emotional reinforce- 
ment ensues, so that, when the stimulus is persistent 
or recurrent, negative adaptation toward it does not 
occur. This emotional reenforcement makes prob- 
able the occurrence of the response as soon as a 
change in the situation allows it. Such a stimulus 
may act throughout a long period, during which it 
interferes with responses to many other stimuli. 
Persistent or recurring stimuli whose responses are 
blocked with a resulting emotional reenforcement 
will be called maintaining stimuli. Maintaining 
stimuli are ultimately removed by the responses they 
themselves provoke. 



62 GENERAL PSYCHOLOGY 

The final response that removes these maintaining 
stimuli, by altering either the external situation or 
the internal state of the animal, is called a consum- 
matory response. The series of responses leading 
up to this final response are called precurrent re- 
sponses. 

Precurrent responses are governed, for the most 
part, by the external situation. When a dog is hun- 
gry, the details of his behavior are his responses, 
instinctive or learned, to the circumstances in which 
he finds himself. The odor of rabbit causes ranging 
about, and in the case of a dog that has once caught 
a rabbit, the odor arouses eating movements in so 
far as they may be given in the absence of food. 

These eating movements, a part of the consum- 
matory response, are interestingly shown by a dog 
or a horse when inaccessible food is displayed. Prob- 
ably a part of the consummatory response is always 
given throughout the period of preparatory acts, 
and this maintains a low threshold for the consum- 
matory response until the opportunity for giving it 
in its entirety arrives. The organs of response in- 
volved in a consummatory reaction are thus in a 
state suitable for use, and the stimuli produced by 
this making ready for action serve, after repeated 
experience, to bring about or to facilitate the pre- 
current responses. This state of readiness in ef- 
fectors may be observed throughout the interval be- 
tween arousal and consummation in such acts as 
mating, hunting, nest-building, quarreling, or search- 



INSTINCT 63 

ing for a lost article. It is this that makes the dog 
range about when he has lost the scent, with the re- 
sult that the scent is again picked up. 

When the trail is lost, the dog is left with an 
abortive tendency to respond to an odor stimulus. 
This results in an emotional reaction that reenforces 
the trial and error behavior by which the scent is 
recovered. 

The blocking of any consummatory response ten- 
dency results in emotion, and this resulting emo- 
tion is in a considerable degree proportional to the 
strength of the blocked tendency. When the swim- 
mer finds his efforts to reach shore interfered with 
by the current, he is overtaken by panic. If you 
tell a child that you have something in your pocket 
that you have decided not to show him, he imme- 
diately becomes excited. Anyone whose efforts to 
catch a train are interfered with becomes emotion- 
ally wrought up. When Shakespeare 's Anthony told 
the people that he held in his hand a document that 
he did not intend to read, their apathy changed to 
interest. Any object whose price renders our pos- 
sessing it impossible becomes by that fact more de- 
sirable. Hampering anyone's movements results in 
his showing rage. Hunting is interesting only if the 
game is difficult to secure. This emotional reenf orce- 
ment derived from the postponement of the 
consummatory response serves to facilitate the 
precurrent responses and so to hasten the consum- 
mation. 



64 GENERAL PSYCHOLOGY 

The final or consummatory response in any chain 
reflex is a convenient basis for classifying instincts. 

Mating behavior is always terminated when copu- 
lation occurs. Food-seeking is always terminated 
by eating. Nest-building ceases when the nest is 
finished. Flight continues until a place of security 
is reached. Combat ends when the foe is killed or 
routed. The body is scratched until the parasite is 
removed. The behavior that leads up to these con- 
summatory responses varies greatly according to 
the situation, but the consummatory responses them- 
selves are highly predictable and so serve as a basis 
for the classification of instincts. Under each of the 
following important consummatory responses will be 
listed a number of chain reflexes to illustrate the 
variety of ways in which diverse precurrent re- 
sponses lead to the same ultimate result. Probably 
few of these response series are purely instinctive. 
Certainly, in the case of man, these utilities are 
served for the most part by learned acts. 

Swallowing Food 

Suckling Striking by snakes 

Following while suckling Striking by fish 

Mouth gaping by young Diving by birds 

birds Stinging and sucking by in- 
Crying and whining of sects 

young Grasping 

Licking Constriction by snakes 

Scratching the ground Biting 

Restlessness due to hunger Pecking 

Following a scent Stalking 



INSTINCT 



65 



Tongue movements of liz- 
ards and frogs 

Chasing 

Creating water currents 

Seizure due to contact 

Hunting cry of owls and 
lions 

Web building 

Carrying home food 

Migration 

Crouching 

Lying in ambush 



Springing 

Lapping 

Chewing 

Grazing 

Eumination 

Fighting and intimidating 
possible competitors 

Threatening wing move- 
ments of pigeons while 
eating 

Hunting in packs 



Copulation 



Preliminary restlessness 
Mating calls 
Drumming by partridge 
Strutting, showing off, and 

dancing 
Coyness of females 
Fighting among males 



Nuptial flight of some 

sects 
Migration 
Courtship 
Affectionate behavior 

ward permanent mate 



in- 



to- 



Securing Shelter 



Kestlessness in the open 

Stereotropisms 

Retirement to shelter in re- 
sponse to darkness 

Seeking a roost high above 
ground 

Burrowing and excavating 

Cocoon spinning and the use 
of secretions in building 

Caterpillar's use of leaves 
in building 

Collecting building materials 



such as mud, sticks, leaves, 

hair 
Rearranging these into nests 

and dens, in trees, on 

ground, in burrows 
Plucking fur and down from 

breast for lining nest 
Dam building by beavers 
Yarding by moose 
Huddling by cattle 
Cooperative nest building of 

insects 



66 



GENERAL PSYCHOLOGY 



Defeating Antagonists 



Restlessness when alone and 
seeking company of fel- 
lows, resulting in herds 
and colonies 
Secretions of skunk 
Discharge of nematocysts 
Taking up posture which 
makes the animal seem 
more formidable 
Snarling, growling, scream- 
ing (often in defense of 
food) 



Cries that summon aid 

Responding to cries for aid 

Flexion of porcupine 

Defensive grouping of herd 

Attack with bill 

Fighting with wings 

Resisting forcible manipula- 
tion 

Struggling, squirming, bit- 
ing when held 

Retaliatory aggression 



Cleanliness 



Licking the body 
Dusting plumage 
Preening 
Scratching 
Biting parasites 
Shaking of wet paw by kit- 
tens 



Picking at foreign objects 

on surface of body 
Cleaning of eggs by ants 
Rolling 
Shaking 
Scratching dirt over filth 



Careful observation of animals will disclose the 
fact that practically none of the items in the above 
list refers to an act that is always executed in the 
same way. An act of flight, for example, is never 
twice the same. The movements depend upon the 
contour of the ground, upon the position of the 
enemy, and upon previously formed habits of all 
sorts. Such " instincts' ' as these are nothing more 



INSTINCT 67 

than the continuance of behavior of many sorts un- 
til a consummatory response has been given. A 
frightened partridge uses many means of escape, 
struggling, running, or flying, until the consumma- 
tory response of reaching concealment terminates its 
activity. 

The Effect of Varying Situations upon 
Preparatory Eesponses 

Greater uniformity in the order of the parts of 
an elaborate "instinct" is seen when each compo- 
nent act changes the situation in a set and charac- 
teristic way. Nest-building is a case in point. A 
shelf under the eaves is a stimulus that may start 
a mated bird in its search for building materials. 
Its return to this spot with material in its mouth 
initiates laying the foundation of the nest. Its 
empty bill starts it ofT again on a search for more 
materials. Return is delayed until its mouth is again 
filled. Its next nest-building movement is deter- 
mined by finding the nest already begun, and so each 
step in the building is governed by the degree of 
completion of the nest at the time. This may be 
demonstrated by partially demolishing a nest which 
has been almost completed. The bird will act then 
much as it did when the nest first reached this stage 
of completion. 

A solitary wasp usually leaves her prey just out- 
side the hole, into which she goes before returning 



68 GENERAL PSYCHOLOGY 

to drag the food into the nest. Fabre demonstrated 
that if the food is removed some distance from the 
nest, the returning wasp will again drag it close to 
the hole, leave it, and again enter the nest. If the 
food is repeatedly moved back, the wasp will behave 
time and again in precisely the same way. 
This nicely illustrates the way in which each act in 
the series is determined by the arrangement of 
stimuli. 

Because of the diversity of conditions from time 
to time, no wasp would repeat exactly its original 
movements in bringing grasshoppers to its hole, and 
no bird would duplicate its original behavior in 
building a second nest. The bird's precurrent re- 
sponses depend upon the nature of available build- 
ing materials and the places where these materials 
are found. A cat prowling about the locality will 
greatly alter the bird's reactions, the sight of food 
may temporarily distract it from its building, but 
eventually the nest is completed after some com- 
bination or another of precurrent acts. 

The wasp observed by the Peckhams was led to 
one preparatory response after another as it came 
by chance upon the small objects surrounding the 
hole. Although its tendency to move small objects 
to the hole is set going by the sight of the open hole 
and the presence of the small objects, the particular 
way in which it behaves is determined by the nature 
and the position of these objects. The sight of the 
stone initiates the effort to move it, but its resist- 



INSTINCT 69 

ance causes the wasp to relinquish it. It will then 
turn to any other material that may catch its eye un- 
til an easily moved object is found, whereupon the 
open hole is covered and ceases to exist as a stimu- 
lus to this sort of behavior. Successful covering 
of the hole is the consummatory response that does 
away with the maintaining stimulus, which remained 
unabated by the precurrent responses. 

There is always a persistence of some maintaining 
stimulus if there is a persistence of the consumma- 
tory response tendency. Courtship is continued 
only as long as some internal or external stimulus 
for copulation is present. Fighting ceases in the 
absence of an antagonist or when rage subsides. 
The terrified person no longer flees when the pur- 
suer is distanced, if the characteristic emotional state 
has passed. 

Instincts, then, are seen to be chain reflexes whose 
serial arrangement is determined by movement-pro- 
duced stimuli. The nervous mechanisms involved 
are established by growth and are not the result of 
training. When the movement-produced stimuli are 
external to the body, the order of responses is more 
variable than when the stimuli reside in the body 
itself. As the common element in so many diverse 
chain reflexes is the particular consummatory re- 
sponse to which they lead, the consummatory re- 
sponse is a valuable basis for the classification of 
instincts when a classification is demanded. 



70 GENERAL PSYCHOLOGY 

Individual Diffebences 

Everyone recognizes the fact that in a group of 
horses or cows or chickens one individual differs 
from another. Some horses are naturally faster, 
and some are naturally slower. One cow is a good 
milker and another cow gives but little milk, even 
though both have had the same care and feeding. 
Chickens vary in size and in the number of eggs they 
will lay. Even in the case of men we recognize dif- 
ferences in height and in pigmentation that are due 
to endowment and not to education. 

It is a tendency of our own times to be less willing 
to admit that from birth one man differs from an- 
other in intellectual ability. To a very great extent, 
however, we are born and not made. Some men are 
gifted with brains, and some are handicapped by a 
natural inferiority for which no amount of training 
will compensate. The great majority of people in 
the world could never graduate from college, because 
of their inadequate intellectual endowment. 

There are very few college students who can run 
a hundred yards in 10 seconds, more who can do it 
in 11, still more who can do it in 12, and probably 
about an equal number who can do it in 13. From 
this point on we find fewer and fewer students whose 
fastest time is 14, 15, 16, or more seconds. If an 
unselected group of students were to start together 
to run the length of a football field, they would be 



INSTINCT 



71 



strung out at the finish in some such way as shown 
in Figure 14. 

ir J%t *t£2* fSse *' Msec t3 sea, /2 sea //sees, /O sea 

man men men men men men men man 

Figure 14. distribution of unselected group of runners 



Their distribution according to speed might be 
represented graphically as in Figure 15. 



5 


































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2 
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77 sec 
man 


76 sec. 
men 


75 sec. 
men 


74 sec. 
men 


73 sec. 
men 


/2 sec. 
men 


77 sec. 
men 


70 sec 
man 



FlGUBE 15. SUBFACE OF FREQUENCY SHOWING THE DISTBIBUTION OF 

THE BUNNERS OF FIGUBE 14 ACCOBDING TO THEIB 

TIME IN SECONDS 

It is possible by the use of mental tests to measure 
with but slight error the amount of a man's innate 
intellectual ability, and to compare the amount of 
this natural endowment with that of people in gen- 
eral. If we were to give our group of students men- 
tal tests, we would find a few of them to be conspicu- 
ously bright, more of them to be a little less intelli- 
gent, a great many of them bunched about the point 



72 GENERAL PSYCHOLOGY 

of average performance, and fewer and fewer at 
points lower and lower in the scale. Such a meas- 
urement of the intelligence of a number of groups is 
represented in the graphs on page 73. 

In general, bright parents have bright children, 
mediocre parents have mediocre children, and dull 
parents have dull children. Striking exceptions to 
this rule should not be given undue weight. The 
handicap of ill health, poverty, or lack of educational 
opportunity, or the advantage of excellent training 
have some effect upon the score that an individual 
makes in intelligence tests. Tests are designed to 
minimize this effect. 

There is no evidence for the common supposition 
that the neurological habits of parents are passed on 
to their children in the form of instincts. There are, 
however, many experimental results that suggest 
that certain of the parents' acquired characteristics 
are passed on to the offspring. All these trans- 
mitted bodily modifications, such as congenital syphi- 
lis or malnutrition, are of a sort quite distinct from 
the neurological changes involved in habit forma- 
tion, and offer no evidence for the belief that educa- 
tion is inherited. Children descended from genera- 
tions of English-speaking ancestors are probably no 
quicker in learning English than are babies of for- 
eign extraction. 

It is not unusual for people untrained in biology 
to think they see contradiction in the two statements 
that " bright parents are likely to have bright chil- 



INSTINCT 



73 



—j !==i !— 



10 20 30 4-0 50 60 70 80 90 100 110 120 130 140 150 160 »70 180 190 200 2 
Score in Alpka Test 

FlGUBE 16. DISTRIBUTION OF ALPHA TEST SCORES FOB COLLEGE STU- 
DENTS AND FOR THE DRAFT ARMY (EQUAL AREAS) 



40 



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20 



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20 40 60 60 100 
Score in Alpha Test 



120 140 160 180 200 



Figure 17. distribution of alpha test scores fob various groups 
in the draft army (equal areas) 



74 GENERAL PSYCHOLOGY 

dren" and that "the results of schooling are prob- 
ably not inherited." This is because they suppose 
that individual differences are all due to training, a 
supposition that is, of course, untrue. 






CHAPTER III 



LEARNING 



Although all babies start life with the same kinds 
of capacities, we find them as adults displaying vari- 
ous individual abilities that have been gained through 
practice and education. They have become judges, 
farmers, carpenters, editors, burglars, and politi- 
cians. Each has developed skill along certain lines. 
Psychology must explain how these diverse habits 
are developed. 

We seldom observe in adults an elaborate act that 
is a pure instinct, and this is because the original 
structure of the nervous system changes as a result 
of use. "We must not, however, fall into the error 
of supposing that when any response is modified by 
learning, it thereupon ceases to be instinctive. The 
instinctive components of any act may be discerned, 
no matter how greatly it has been transformed by 
training. 

The modifications of instinctive behavior that re- 
sult from use are of two sorts. One sort of learn- 
ing results in the attachment of a response to a stim- 
ulus that did not provoke it originally. This is illus- 
trated by such a common act as reaching for the tele- 
phone receiver when the bell rings. A baby or a 

75 



76 GENERAL PSYCHOLOGY 

savage does not respond in snch a way to this stimu- 
lus. Another sort of learning is a modification of 
the ease with which a response may be elicited. Un- 
der certain conditions a person may develop a ready 
anger toward interruptions when at work, and un- 
der other conditions he may develop toward the same 
occurrences an increasing toleration. 

All habits, no matter how complex, are the results 
of these easily understood changes in stimulus-re- 
sponse mechanisms. We shall first consider the 
modifications in the ease with which responses are 
brought about, and later, under the heading "The 
Conditioned Response," we shall discuss the at- 
tachment of responses to new stimuli. 

Positive Adaptation 

Repeated working of a stimulus-response mechan- 
ism, especially if the stimulus is just above the 
threshold of response, results in lowering the thresh- 
old, in decreasing the reaction time, and in increas- 
ing the vigor with which the response is given. This 
effect of repeated working is called positive adapta- 
tion. 

Because of practice, the lookout on board ship is 
able to signal the approach of a vessel more readily 
than is the landsman who stands beside him. If the 
situation is such that we always get up when the 
alarm clock rings, the clock may be moved farther 
and farther from the bed on successive nights, un- 



LEARNING 77 

til we are finally aroused by a sound much too faint 
to have gotten us out of bed on the first morning. A 
physician may develop a positive adaptation to the 
telephone at night, while his wife sleeps through the 
disturbance. His wife, on the other hand, is often 
the one who responds to the crying of the baby. The 
suburbanite develops a sensitive ear to the whistle 
of the early train; the bank teller is quick to detect 
counterfeit money ; the woodsman notices signs that 
escape the city dweller; and all of us turn when a 
dime is dropped even on a noisy street. If we were 
to see two signboards side by side and lettered in 
the same type, one bearing the words BULL 
DURHAM and the other the nonsense words RAHD 
LULBUM, and if these were just near enough to 
enable us to read the first of these signs, we would 
not be able to decipher the second, though the same 
letters occur on the two signs. We do not develop 
positive adaptation to all stimuli that act upon sense 
organs, but only to those that provoke a response. 

When we first learn to perform an act in response 
to a new stimulus, the time involved in giving the 
response is much longer than it is at a later period, 
after practice. This shortening of reaction time is 
best studied where a large number of stimuli are 
responded to in novel ways, as in learning to type- 
write, to send or receive telegraphic messages, to 
translate a foreign text, or to take dictation 'in short- 
hand. By measuring the performance of any of 
these acts during successive practice periods, and 



78 



GENERAL PSYCHOLOGY 



by plotting these measurements, we get what is 
called a practice curve. An illustration is given in 
Figure 18. 

In telegraphy the practice curve for either send- 
ing or receiving shows that more and more words 













































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Trials 



10 



Figure 18. curve of practice in mirror drawing, each ordinate 
represents the average time of 50 subjects. the function 
practised was drawing a circle between the double lines. the 
figure was screened from the subjects and visible only in a 
mirror. the outer circle was four inches in diameter. the 
track between the two circles was an eighth 
of an inch wide 



may be handled in a given time as practice continues. 
There is, of course, a limit to such improvement, and 
the telegrapher finally approximates his maximum 
speed. As this limit is approached the curve flat- 



LEAENING 79 

tens out. Thus the first part of practice is rela- 
tively more fruitful than the last part. 1 

Through use, the tendency of a response to follow 
its stimulus becomes better established. This 
greater tendency to sequence is shown not only in 
a lowered threshold and a shortened reaction time, 
but in an increased resistance to distraction. The 
practised act is performed in the face of altered con- 
ditions and in spite of internal variations that would 
have prevented the reaction originally. 

Positive adaptation is gradually lost after prac- 
tice has been discontinued. This slow disappear- 
ance of positive adaptation is called forgetting, and 
may be measured just as the appearance of posi- 
tive adaptation may be measured. The rate of for- 
getting, as graphically represented, is at first rapid. 
(See Figure 25.) As time passes, the loss of prac- 
tice effects takes place at a slower rate, and even 
after years of disuse, a stimulus-response mechanism 
may still show traces of positive adaptation. Horse 
buyers determine whether a horse has ever had 
mange by stroking the horse's flank. A horse that 
has had mange, and has through practice developed 
positive adaptation of the natural skin-biting re- 
sponse, will respond years later by a quivering of 
the lip. 

i Thorndike, "Notes on Practice, Improvability, and the Curve of 
Work," American Journal Psychology, 1916, pp. 550-565. Hill, Re- 
jall, and Thorndike, "Practice in the Case of Typewriting," Ped- 
agogical Seminar, 1913, pp. 516-529. Lashley, "The Acquisition of 
Skill in Archery," Carnegie Institute, 1915. 



80 GENERAL PSYCHOLOGY 

Anyone who has narrowly escaped being struck by 
lightning shows a greater fear response than before 
to the distant thunder storm. If we have been pro- 
voked to anger by another's outrageous act, he may 
arouse our anger again by the most trivial discour- 
tesy. At first this might seem to be evidence that 
positive adaptation results best from responses to 
intense stimuli but this is probably not so. 

It requires a very intense stimulus to call out an 
extensive, diffuse, and complete emotional response, 
although parts of the response may be given to a 
weak stimulus. Once the response has been called 
out in its entirety, the elements originally having 
high thresholds are more easily elicited and the act 
as a whole is bound together by what we shall later 
call conditioning. This explains why a child who 
has been thoroughly frightened shows cowardice on 
slight provocation. His entire fear mechanism has 
been called into action, and the partial fear response, 
which is ordinarily given by children who have never 
known abject fear, gives place to a more complete 
expression upon insignificant occasion. The child 
who has often been teased to a point of rage, shows 
positive adaptation of those parts of the rage re- 
sponse that are naturally more difficult to elicit, and 
thus develops a bad temper toward small grievances. 

Negative Adaptation 

If a subliminal stimulus is repeated with gradu- 
ally increasing intensity, the response may not oc- 



LEARNING 81 

cur when the stimulus reaches or even passes the 
usual threshold point, and in this way, especially if 
the response is never given, the threshold of re- 
sponse will be raised. This is called negative adap- 
tation. 

If the temperature of the room falls gradually, 
we fail to notice it, but if, for any reason, it suddenly 
becomes cold, we react to the change. If the cost 
of living were to double over-night, there would be 
public disorder the next day, but, because the dou- 
bling is a gradual process occupying several years, 
the situation remains below the threshold for rioting. 
The physician is inured to the suffering of others 
by witnessing it repeatedly, and by the necessary 
inhibition of any useless expression of sympathy. 
A child who is afraid to sleep without a light may 
become adapted to sleeping in entire darkness by a 
gradual reduction of the intensity of the light on 
successive nights. The practised person while using 
a microscope, shows negative adaptation for stimuli 
affecting his left eye. The disobedient child is in- 
different to his parent's call because he has failed, 
on many occasions, to respond. In order to train a 
dog to come when called, the expert dog trainer 
never uses the dog's name except in summoning him. 
The visitor in a household is disturbed by the chil- 
dren's noise, while the parents may have become 
adapted to it. Many parents also become negatively 
adapted to their children's questions and are sur- 
prised when their attention is called to this. 



82 GENERAL PSYCHOLOGY 

James thought it unfortunate that man is en- 
dowed with a fear response, the severity of which 
often renders him helpless in the face of danger. 2 
Nearly anyone, if he were compelled to walk an 
I-beam high above the street, would be seized by 
panic and would fall. But James overlooked the fact 
that this original over-supply of fear is of value 
when it is ultimately decreased by negative adapta- 
tion to the dangerous situation. If fear were not 
found in excess in the ingenuous man, the danger- 
adapted man would often die of foolhardiness. Ex- 
cessive embarrassment handicaps the adolescent in 
the presence of strangers, but we all dislike the adult 
in whom negative adaptation has been so thorough- 
going as to leave no traces of reticence. 

A man is saved from feeling distaste for his age- 
ing wife because wives grow old gradually, and he 
becomes negatively adapted to characteristics that, 
were they to occur suddenly, would discourage his 
affection. The proper way to break a horse to the 
saddle is to accustom him first to a blanket, next 
to blanket and surcingle, then to the saddle in addi- 
tion. Later, to adapt him to the pressure of the 
rider, a bag of feed of gradually increased weight 
may be strapped across the saddle. Successful 
breaking depends upon keeping the stimuli within 
the horse's growing toleration. A disliked food 
taken in quantities sufficiently small to excite no 
disgust, may be eaten in gradually increasing 

2 James, Principles of Psychology, vol. ii., p. 419. 



LEARNING 83 

amounts on successive occasions until a large portion 
does not cause aversion. Crowding the threshold 
for intolerance of a stimulus, without reaching the 
breaking point, makes for increased tolerance. 

Another way in which negative adaptation may 
result is by the failure of the response, though given, 
to rid the animal of the stimulus. In such a case, 
the stimulus-response mechanism becomes fatigued, 
and the response is given less and less energetically 
to the persistent stimulus, until all response ceases. 
The horse that is broken by the cow-puncher method 
becomes accustomed to the saddle when his efforts 
to dislodge it repeatedly fail, and so, while he may 
always make slight movements of resistance while 
being saddled, the threshold of resistance is perma- 
nently raised. 

We have said that negative adaptation may be 
brought about in two ways. The repetition of a sub- 
liminal stimulus may cause it ; or it may result when 
a stimulus persists in spite of the animal's respon- 
ses, after fatigue has raised the threshold. There is 
a third kind of situation that results in negative 
adaptation. An eliciting stimulus may be rendered 
ineffective by the presence of an inhibiting stimulus, 
and, the threshold of response being thus raised, 
negative adaptation results. In this way children be- 
come negatively adapted to temptingly accessible 
food by the inhibiting threat of punishment. In 
Triplett's experiments, perch were separated from 
minnows, which are their natural food, by a glass 



84 GENERAL PSYCHOLOGY 

partition in the aquarium. A perch would at first 
dart toward a minnow, but would strike its head 
against the glass. In time the big fish became nega- 
tively adapted to the presence of the minnows. The 
partition was then removed and the minnows mixed 
safely with their natural enemies. This case, though 
an example of negative adaptation, involves a con- 
ditioned response, and this will be discussed below. 3 
Both negative adaptation and summation follow 
upon the repetition of subliminal stimuli, though 
they are quite different results of such repetition. 
It is the length of the intervals between the stimuli 
that determines which one of these two effects will 
occur. A series that will have a summation effect, 
and finally bring about a response, may lose that 
effect if the length of the intervals between stimuli 
is increased, in which case negative adaptation, or 
the permanent raising of the threshold, takes place. 
These alternative possibilities are seen not only in 
behavior but in the physiological responses of the 
body to drugs. If one dose rapidly follows another, 
a cumulative effect results, but if gradually increas- 
ing doses are given at widely separated intervals, 
negative adaptation results, so that the patient may 
come to tolerate amounts of the drug that would 
have been fatal at the outset. 



3Triplett, "The Educability of the Perch," American Journal of 
Psychology, vol. 12, p. 354. 



LEARNING 85 

Transitory Changes of Threshold During a Single 
Practice Period 

If a considerable time has passed since an act was 
last performed, the threshold of response is found 
to be unusually high and the reaction time to be un- 
usually long. "When a ball player begins his day's 
practice, he is less sensitive to situations and slower 
to respond than he is after fifteen minutes of warm- 
ing up. In golf we take a few practice strokes be- 
fore driving from the first tee in order to pass this 
period of sluggish reaction. The slowness and the 
weakness of response and the high threshold that 
characterize the beginning of any activity we shall 
call initial torpor. 4 

Initial torpor is seen in simplest form in the con- 
tractility of the muscle-nerve preparation or in a 
spinal reflex. When it is exhibited in such a com- 
plex act as game playing or factory work, other ele- 
ments enter in to make it appear greater than it 
really is. When work has first begun, negative 
adaptation to distraction has not yet occurred. 
Passers-by, noises, and room temperature, all dis- 
turb us at first, but later, through negative adapta- 
tion, are disregarded. 

Another obscuring factor is the hangover of re- 
sponses recently given. Conversation just engaged 
in leaves the talker for some time afterward still 

* Thorndike, Educational Psychology, vol. ii. 



86 GENERAL PSYCHOLOGY 

talking to himself. If we turn from chess to letter 
writing, a tendency to make chess moves hampers 
the composition of our first paragraph. The student 
who has hurried to avoid being late at class is agi- 
tated for some time after taking his seat. This hang- 
over of recent movements is due partly to the per- 
sistence of emotional reenforcementl 

A complex habit is made up of many parts and in- 
volves many action systems. Initial torpor attaches 
to each part and to each emotional reenforcement. 
It is dissipated in the parts of lowest threshold be- 
fore it disappears in others. As one part after 
another of the entire act is brought into play by ten- 
tative beginnings, and by the stimuli that these be- 
ginnings bring to bear upon us, the several parts of 
the act successively lose their sluggishness and com- 
bine into the act as a whole. After such warming up 
the entire habit has a lowered threshold. 

Every time work is begun after a long period of 
rest, initial torpor is found to be present. If the 
practice curve is still rising and has not reached a 
plateau, the absolute amount of initial torpor to be 
overcome is less at the beginning of each successive 
practice period. There is no difference in kind be- 
tween the positive adaptation shown in overcoming 
initial torpor and the positive adaptation that is the 
gradually decreased reaction time and lowered 
threshold of an act practised at intervals for many 
days and graphically represented by the practice 
curve as a whole. 



LEARNING 87 

Toward the end of the doubleheader the ball 
player again becomes less sensitive to situations and 
slower in response, and this we call fatigue. Toward 
the end of the shift in the factory the number of ao- 























































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6 7 8 9 
O'CLOCK 



10 11 12 1 



FlGUEE 19. DISTRIBUTION OP GERMAN INDUSTRIAL ACCIDENTS 

THROUGHOUT THE WORKING DAY, IN PART THE RESULT 

OP FATIGUE (AFTER GOLDMARK) 

cidents increases. 5 The third time around the links 
we make a poor score. Fatigue is the slowness of 
response, the weakness of response, and the high 

6 Goldmark, "Fatigue and Efficiency," Russell Sage Foundation, 
1912, p. 71. 



88 GENERAL PSYCHOLOGY 

threshold of response that finally occur if any activ- 
ity is continued long and vigorously. It is a tempo- 
rary effect of repeated action, and a period of rest 
causes it to vanish. 6 

Variations in response threshold may result either 
from variations in the conductivity of synapses, or 
from variations in the contractility of muscles. The 
high threshold that characterizes initial torpor seems 
mainly the result of resistance at synapses, a condi- 
tion that is reduced by practice. The high response 
threshold in fatigue is the result chiefly of a reduced 
contractility in the muscle, which is brought about 
by exercise. 

The Conditioned Response 

How may a response be provoked by a new stimu- 
lus? Let us take the case of a dog that sees a cat. 
On seeing the cat he barks. Suppose that while 
looking at the cat he hears his master say the word 
"cats", and that these two stimuli occur together 
several times. Later if he hears the word "cats", 
although there is no cat present, he will bark. This 
response first called forth by the sight of a cat is 
now provoked by a new stimulus, namely, the sound 
of a word. When a response is elicited by a new 
stimulus, because of the fact that the new stimulus 
has occurred along with the old, it is called a condi- 
tioned response. 

6 Thorndike, "Fatigue in a Complex Function," Psychological Re- 
view, 1914, pp. 402-407. 



LEARNING 89 

If a percussion hammer falls upon the patellar 
tendon, a spinal reflex is elicited involving the con- 
traction of the quadriceps muscle. This is called the 
knee-jerk. In 1902, Twitmyer demonstrated that if 
a bell was sounded each time that a hammer fell on 
the patellar tendon, it was possible, after consider- 
able practice had occurred, to elicit the knee-jerk by 
the auditory stimulus alone. 7 To-day a reflex re- 
sponse to a substituted stimulus is called a condi- 
tioned reflex, because the substituted stimulus is one 
of the conditions accompanying the original stimu- 
lus. Pavlow discovered that a conditioned salivary 
reflex could be secured from dogs. Certain foods, 
when eaten, cause a copious secretion of the salivary 
glands. He found that, if some visual or auditory 
stimulus is made the invariable accompaniment of 
the saliva- exciting food, the accompanying condition 
will provoke the salivary flow in the absence of the 
original food stimulus. Watson and Lashley dem- 
onstrated the conditioned salivary reflex in man as 
well as other conditioned reflexes in both dogs and 
human beings. 8 

The principle that one of the accompanying condi- 
tions of a stimulus responded to may later become a 
substituted stimulus for the response, applies to all 
associative learning. If a bell is attached to a dog's 
tail and the dog is petted in a way to make him wag 
his tail, the sound of the bell will be an ever present 

i Twitmyer, "A Study of the Knee-jerk," Philadelphia, 1902. 
s Watson, Psychology from the Standpoint of a Behaviorist, pp. 
29-38. 



90 GENERAL PSYCHOLOGY 

condition under which the caudal response is elicited. 
After considerable wagging of the belled tail the bell 
may be removed and the wagging produced without 
petting when the dog hears the bell rung. In order 
to make a dog respond to his name when called, the 
trainer secures this response first to food and then, 
while the dog is coming, speaks his name. In time 
the sound of the name becomes the substituted stimu- 
lus for approach. 

If a number of photographs is presented to a sub- 
ject each one being named by the experimenter and 
then by the subject as he looks at the photograph, 
a conditioned response will be established in time 
toward each picture, so that the subject will call it 
by the proper name. The previous stimulus for this 
response was the word spoken by the experimenter, 
and the substituted stimulus is the accompanying 
visual representation. In like manner probably any 
response may be conditioned by accompanying stim- 
uli in the absence of the original stimulus. Nausea 
may occur at the mere sight or odor of food in which 
a nauseating medicine was once taken or that was 
eaten during a storm at sea. This fact was made 
use of in curing the whiskey habit. Mark Twain 
found it difficult to speak on serious matters in public 
because he himself constituted a conditioning stimu- 
lus that always provoked laughter in his audience. 9 



9 Interesting examples of conditioned emotional responses are de- 
scribed by Locke in his Essay Concerning Human Understanding, 
Book 2, Chapter 33. 



LEARNING 91 

Conditioned Emotional Responses 

An interesting example of a conditioned response 
is seen in the attachment of an emotional expression 
to some situation that originally had no power to 
bring out the emotion. Probably each emotion is 
originally provoked by a very limited number of sit- 
uations. Tickling is the adequate stimulus for caus- 
ing the baby to smile, but the baby may learn to 
smile at sight of the person who has tickled him be- 
cause he has been exposed simultaneously to the 
tickling and to the sight of the tickler. He is not 
originally afraid of the sight of a dog and indeed 
will ordinarily reach toward it, but once frightened 
by its bark or knocked down by its rush the subse- 
quent sight of the dog is sufficient to cause the ex- 
pression of fear. 10 The dog once kicked by the milk- 
man will fly into a rage at sight of him, his rage re- 
sponse being originally provoked by the kick, but 
conditioned by the appearance of the man. 

It is in this way that we learn to show anger, joy, 
fear, love, disgust, and other emotions in response to 
those occurrences of life that are apt to be followed 
by events that make these responses appropriate. 
Thus we anticipate the attack of a familiar foe, or 
by an early withdrawal avoid too close proximity to 
the frightful object. Many of our fears, likes, or 

10 An experiment in establishing conditioned emotional responses 
in an infant is described by Watson and Eayner, "Conditioned Emo- 
tional Reactions," Journal of Experimental Psychology, 1920, pp. 
1-14. 



92 GENERAL PSYCHOLOGY 

dislikes are conditioned responses to stimuli that 
have only a chance temporal connection with their 
natural provocation. A celluloid collar in itself is 
neither alluring nor repulsive, and our dislike of 
such an article of dress is dependent upon the fact 
that we have always experienced it in connection 
with a wearer who is not too scrupulous as to his 
personal cleanliness. Everyone builds up a set of 
emotional tendencies through this process of associa- 
tion, so that his adult attitude toward the experien- 
ces of life is fitted to the culture into which he has 
been born. 

Particular melodies become associated with the 
words of songs and with emotional expressions that 
have been called out by these words. Although at 
first only the words may have had the power to 
arouse the emotions in question, the music itself, in 
the absence of the words, will later have the same 
effect. Easter and Christmas music, the melody 
to which sentimental words were sung, patriotic 
airs, the words of which originally excited patriotic 
emotions, or the music sung at the funeral of 
a friend, will long afterward revive the emotional 
expression of w r hich they were at first the incidental 
accompaniment. Conversely, music itself may di- 
rectly arouse emotional responses, and this fact is 
made use of to reenforce the conviction that the at- 
tending words but partly establish. The stirring 
airs of the camp meeting or the patriotic rally bring 
many to the mourner's bench or the recruiting office 



LEARNING 93 

who would remain sinners or slackers if appealed to 
by words alone. 

Emotional expressions as a whole may be attached 
to new stimuli, and in inappropriate situations con- 
stitute many of the psychoneuroses. If in the pro- 
cess of courtship a person is placed in a position to 
arouse great fear, the emotion of fear may become 
attached to all erotic stimuli, and what is known as 
an anxiety neurosis may develop. Cases have been 
reported in which an aversion for small rooms can be 
attributed to the subject's having fainted at one time 
in a small close room; in which a fear of buzzing in- 
sects followed a child's being frightened by a hum- 
ming bird that entered a window and flew rapidly 
about the child's head; in which a horror of bells 
was caused by a church bell's ringing at a time when 
great depression, resulting from her mother's death, 
possessed the subject, who believed herself responsi- 
ble for her mother's illness. Such conditions often 
call for treatment at the hands of a psychologist. 11 

The way in which these bad habits of emotional re- 
sponse are cured is to attach a rival response to the 
stimulus that arouses them. If, for example, a per- 
son shows a morbid aversion towards touching ab- 
sorbent cotton, the psychoanalyst attempts to dis- 
cover the origin of this response by delving into the 
subject's past. It may be found that as a child the 
subject once handled some dirty cotton that had been 

11 Hollingworth, The Psychology of Functional Neuroses, New York, 
1920. 



94 GENERAL PSYCHOLOGY 

used as a surgical dressing, and that he was at that 
time scolded by a disgusted parent. For practical 
purposes it probably does not matter whether this 
event was the occasion of the subject's original dis- 
taste for cotton, provided the subject himself is con- 
vinced that this was the real cause. With this start, 
the psychoanalyst proceeds to lower the threshold 
for the recollection of this childhood event, and so 
makes certain that the subject will always think of 
the event when cotton is seen. The subject is then 
told that little children can not be held responsible 
for failure to avoid unsanitary acts, that the sub- 
ject himself was in no way to be blamed for what 
he did, that certainly no harm resulted from his act, 
and that, indeed, the whole matter is very ludicrous 
as we look back upon it. 

In this way there becomes attached to the sight of 
cotton the tendency to discuss the childhood event 
and for such discussion to be accompanied by self- 
satisfaction and amusement. If this line of response 
is sufficiently practised and sufficiently reenforced 
by verbal rationalization, it develops a threshold 
that is lower than that of the aversion response, 
and thus the aversion habit is cured. 

The Substitution of Similar Stimuli 

An act may be learned in response to one situation 
and later given to another that is partially identical, 
even though the common elements in the two situa- 



LEARNING- 95 

tions are wholly incidental and irrelevant. This 
substitution does not involve the process of condi- 
tioning. It is nicely illustrated by many false moves 
in everyday life. The following cases have been ob- 
served recently. A person was about to make tea. 
Instead of turning on the gas for the Bunsen burner, 
lighting it with a match, turning on the water faucet, 
filling the kettle, and placing the kettle over the 
burner, he made the mistake of turning on the water, 
lighting the match, and placing the match under the 
faucet. The mistake, of course, was due to the sim- 
ilarity of proprioceptive stimulation involved in 
turning the gas cock and opening the water faucet, 
the false response being practically the same as the 
gas-lighting response. Another example of the sub- 
stitution of one stimulus for another, because of 
partial identity, was found in the case of a man who 
entered a shop to purchase a newspaper and who 
dropped his money on the floor. He picked up the 
money and left the shop without securing the paper, 
and did not appreciate his mistake until he was some 
distance away. Here the responses of picking up the 
coin and of picking up the newspaper are almost 
identical, and the mere act of picking something up 
was the usual stimulus for leaving the shop. 

Facilitating Effect of Conditioning Stimuli 

If a dog that has been trained to respond to the 
word " cats' ' sees a cat at such a distance that the 



96 % GENEBAL PSYCHOLOGY 

stimulus is below the threshold for chasing, his mas- 
ter may urge him on by using the word and he may 
at once start in pursuit. In this way the sound of 
the word "cats", although not now the sole cause 
of the response, facilitates the response, because it 
occurs in conjunction with the actuating stimulus. 

Illustrations of these conditioning stimuli and 
their resulting facilitation are plentiful in everyday 
life. The literary man accustomed to writing while 
smoking a pipe finds it difficult to work without the 
pipe in his mouth. The clergyman is moved to 
greater eloquence when wearing his cassock, and 
would find it difficult to preach a sermon on the 
street corner. The college instructor, because he 
frequently uses chalk during lectures, finds facilita- 
tion to his speech through holding a piece of chalk in 
his hand. Our familiar surroundings increase our 
personal efficiency, and this law gives a psychological 
justification to the so-called right of personal prop- 
erty. 

A man sleeps best in his own bed, not only because 
he is negatively adapted to the distracting stimuli 
of his neighborhood, but because he has gone to sleep 
many times in these surroundings and they have a 
facilitating effect in producing slumber. A child 
often refuses to sleep unless covered by a familiar 
blanket, or allowed to suck his thumb, or permitted 
to take a certain doll to bed with him. 



LEARNING 97 

Neural. Basis of Learning 

Conditioned responses involve the formation of 
new pathways and the possibility for this is best 
afforded by the intricate association fibres of the 
cortex. When a neural arc is acting, impulses re- 
ceived from sense organs not previously connected 
with this neural arc are likely to be drained into its 
outgoing motor pathway. This drainage establishes 
new synapses and thus connects new sense organs 
with the responding muscle or gland. This is the 
neural basis of the conditioned response. It may be 
best understood by consulting the diagram in Fig- 
ure 20. 

Impulses aroused by accompanying conditioning 
stimuli are drained into the motor system that is 
active at the time. Thus when the original stimulus 
and the conditioning stimulus act together, the com- 
bined energy from the two is drained into a single 
motor system. For this reason the conditioning 
stimulus facilitates the action of the original me- 
chanism and this mechanism may act with a stimu- 
lation less intense than was first required. 

The changes in the nervous system that account 
for positive adaptation are presumably an increase 
in conductivity at synapses. Eesistance at a synapse 
is decreased each time a nervous impulse passes 
through it, and an improvement in conductivity of 
the synapse results from use. A lessened resistance 



98 



GENERAL PSYCHOLOGY 




MUSCLES 



Figure 20. establishing a conditioned response, the first 
stimulus that sets the dog to running and barking is the 
sight of the cat. if, at the same time, he is stimulated by 
the word "cats" pronounced by his master, the impulses re- 
sulting are drained into the system that is acting, and a new 
pathway is established. after practice, this sound becomes the 
conditioning stimulus that may set the dog into 
activity in the absence of any cat 



LEARNING 99 

in the synapses of a neural arc means a reduced 
threshold of response. 

The nervous changes underlying negative adapta- 
tion are rather more hypothetical. We may sup- 
pose, however, that an impulse that starts to tra- 
verse a neural arc, but which does not reach the 
terminal effector, must of necessity drain into other 
pathways. Any motor pathway, when active, may 
drain to itself afferent impulses from other neural 
arcs. "With use, drainage pathways become better 
established, with the result that later impulses show 
a lessened tendency to traverse the original neural 
arc and an increased tendency to traverse the new 
drainage pathway. Thus negative adaptation of 
one response always means the substitution of 
another response. This substitution is brought 
about when drainage establishes new association 
pathways. In this way impulses from the stimulus 
that is apparently disregarded actually reenforce 
some routine activity. The drained impulses may 
reenforce respiration, or any system that is active, 
or they may occasion emotional responses. Thus 
they establish a habit of doing something other than 
the act to which negative adaptation has been de- 
veloped. 

Associative Inhibition 

If, while reading aloud, we encounter a word that 
we have been in the habit of pronouncing in either 
of two ways, a pause in reading can be noticed. 



100 GENERAL PSYCHOLOGY 

This is because there are two pathways of discharge 
available for the afferent impulse. The two respon- 
ses, being incompatible, can not both be given, and 
mutual inhibition from a single stimulus is the re- 
sult. This interference is an event in the central 
nervous system, and may occur without causing a 
contraction of the muscles involved in either of the 
incompatible responses. Practice of an incorrect 
performance of any act makes later learning of the 
act in its correct form more difficult than if the in- 
correct performance had not occurred. If a part 
of the multiplication table is wrongly learned, more 
practice of the correct form is required than is re- 
quired for attaining equal facility in a part of the 
multiplication table that has never been attempted. 
The attachment of two incompatible responses to a 
single stimulus, which results in their mutual in- 
hibition, is called associative inhibition. r 

The Sekial Response 

» 
Each movement a man makes is likely to bring him 
into new relations with his surroundings and thus 
cause new stimuli to act upon him. In this way a 
stimulus produces a response, this response a new 
stimulus, this stimulus a new response, and so on 
until tiiere are no more stimuli that cause movement. 
If such a series is repeated many times, the man's 
responses show positive adaptation to each of the 
several stimuli, so that the time required for going 



LEARNING 101 

through the series of responses is shortened. En- 
tering our own house is an act we all perform 
smoothly and quickly. The first time we entered the 
house, however, we were less quick in opening the 
gate and in closing it after us, slower in mounting 
the unfamiliar steps, finding the key, and unlocking 
the front door. As we repeat the act day after day 
our entrance takes less and less time. This increase 
in speed is in part a simple positive adaptation of 
response to the successive stimuli of gate, steps, 
key, and lock. 

In addition to the stimuli that affect our eyes and 
to which our responses are given, there is another 
series of stimuli that the responses themselves cause 
and that accompany the visual stimuli. These are 
stimuli to the proprioceptors in the muscles and ten- 
dons caused by the movements of manipulation and 
walking, and the stimuli to the end organs of touch 
that these movements occasion. These movement- 
produced stimuli play a role similar to that of all 
otjier stimuli that are incidental to the actuating 
stimulus, in that they serve to condition the response 
when the actuating stimulus is absent, or to facili- 
tate the response when they occur time after time 
along with the actuating stimulus. This facilitation 
is a cause for the increased speed of the serial re- 
action in addition to the positive adaptation men- 
tioned above. 

In like fashion a person learns his way about the 
house, at first depending upon his eyes to avoid ob- 



102 GENERAL PSYCHOLOGY 

stacles and to find the easiest route from place to 
place. As all movements are accompanied by pro- 
prioceptive stimulation, in time he is able to dis- 
pense with visual stimuli and to find his way about 
in the dark. Tying a cravat or lacing a shoe is at 
first dependent upon visual stimuli, but later each 
component movement becomes almost wholly condi- 
tioned by the kinaesthetic and touch stimuli occas- 
ioned by the preceding movement. A pianist while 
learning a musical composition depends upon his 
score as a guide in making each movement. Later, 
because each movement becomes the cue to the next, 
because of its stimulation of sense organs in the 
muscles, and because of its producing sounds that 
stimulate the ear, the musician may throw away his 
score. If a printed page is read aloud many times, 
the book may be closed and the passage spoken from 
memory. This is in part the result of the sound of 
each word becoming the conditioning stimulus for 
the movements producing the next word, and in part 
the result of the accompanying kinaesthetic stimu- 
lation playing a similar role. In learning to write 
we first depend upon copy books, but later, in addi- 
tion to the conditioning proprioceptive stimulation, 
the sight of the first letter of the familiar word 
that the pen forms becomes a conditioning stimulus 
for writing the second letter, and this a conditioning 
stimulus for the third, and so on. 12 

12 Concerning the neural basis of chain reflexes and serial re- 
sponses see Herrick, Introduction to Neurology, and Sherrington, 
Integrative Action of the Nervous System, p. 18 Iff. 



LEARNING 103 

When a person is learning to dance, lie makes one 
movement after another in response to each verbal 
direction of his instructor. While one movement is 
being made the instructor gives directions for the 
next, so a proprioceptive stimulation caused by the 
preceding movement accompanies the instructor's 
verbal stimulus. With repetition of the stimulus- 
response series, these proprioceptive stimuli be- 
come conditioning stimuli and serve to link together 
the responses in the absence of verbal direction. 
When this dependence of each movement upon the 
muscle stimulation of the preceding movement oc- 
curs, we say the person has learned to dance. The 
way in which this substitution of movement-pro- 
duced stimuli for the original exteroceptive stimuli 
comes about is illustrated in Figure 21. 

The facilitating effect of accompanying condition- 
ing stimuli is seen in what might appear at first sight 
to be cases of simple positive adaptation. Thus pos- 
itive adaptation to the alarm clock is shown by the 
conscientious person who, always responding, is 
eventually stimulated to rise by the faintest tinkle. 
He is aided in rising, however, by the fact that his 
first start of surprise has been followed by the move- 
ment of his arm in throwing off the covers, and this 
in turn by sitting up, feeling for his slippers, put- 
ting them on, and rising to his feet. When this series 
of movements is made, the proprioceptive stimuli 
occur in a certain order and become conditioning 
stimuli that serve to iix the sequence of responses. 



104 



GENERAL PSYCHOLOGY 



Positive adaptation plays its part in speeding 
up each step in the chain reaction, but the most im- 
portant factor in maintaining the response as a 
whole is the series of conditioning proprioceptive 
stimuli. 

Such conditioning stimuli as are mentioned above 
are involved in the movements themselves, and are 
not subject to the vagaries of the external environ- 



fteceptors 




AfuscZes and 
Proprioceptors 



p, H* % "4 



Figure 21. diagrammatic representation of the formation of a 
serial-response habit (after dunlap). the series of responses 
is at first the result of the successive stimulation of the 
distance receptors shown at the top of the figure. during 
practice this stimulation is accompanied by the stimulation 
of proprioceptors in the acting muscles. this proprioceptive 
stimulation gives rise to nervous impulses that are drained as 
indicated by the arrows into the acting system and in time 
the series of responses may be elicited by these movement- 
produced stimuli, only the first of the distance 
receptor stimuli being necessary 

ment. Hence they serve to stereotype the response 
as a whole in a way that would not be possible if the 
organism had to depend for guidance wholly on ex- 
ternal situations whose regular occurrence is uncer- 



LEARNING 105 

tain. These orderly response series, now partly in- 
dependent of the environment, constitute most of 
our skilled acts and enable man with his aptitude 
for such habit formation to dispense with the fixed 
instinctive order of responses characteristic of the 
behavior of the lower animals. This is not because 
man has more proprioceptors or other sense organs 
than have lower animals, but because in man these 
sense organs have more extensive connections in the 
central nervous system. The resulting plasticity en- 
ables man to adjust himself to various cultures, oc- 
cupations, and environments. 

The Effects of Peactice on the Serial Response 

The effects of practice in establishing a serial re- 
sponse have been measured by Ebbinghaus, who de- 
termined the number of repetitions necessary for 
learning a series of nonsense syllables so that it 
might be reproduced once without error. By a non- 
sense syllable is meant such a sound combination as 
nis, geg y f of, gol, nen, or kev. 13 

The longer the series, the greater is the number 
of repetitions required for learning. Ebbinghaus 
could repeat a series of seven syllables after having 
said it once, whereas a series of 12 syllables required 
about 16 repetitions, a series of 16 syllables required 
30 repetitions, one of 24 syllables, 44 repetitions, and 

is See: Lyon, Memory and the Learning Process; Meumann, Psy- 
chology of Learning ; and Ebbinghaus, Memory. 



106 



GENERAL PSYCHOLOGY 

These are repre- 



one of 36 syllables, 55 repetitions 
sented in Figure 22. 

These results may be stated in another way, 
namely, in terms of the actual amount of work done 
to learn each series. Repeating 12 syllables 16.6 



uu--~ * 








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10 

LENGTH OF SERIES 



20 



30 



FiGUEE 22. THE NUMBER OF REPETITIONS REQUIRED FOR ESTABLISHING 
SERIAL RESPONSES OF VARIOUS LENGTHS. THE MATERIAL LEARNED 
CONSISTED OF SERIES OF NONSENSE SYLLABLES. A REPETITION CON- 
SISTS OF SAYING ANY SERIES ONCE, IRRESPECTIVE OF THE LENGTH OF 
THE SERIES. THE SYLLABLES WERE SPOKEN AT THE RATE OF 
150 A MINUTE (AFTER EBBINGHAUS ) 

times involves pronouncing 199 syllables ; repeating 
16 syllables 30 times involves pronouncing 480 syl- 
lables ; repeating 24 syllables 44 times involves pro- 
nouncing 1,056 syllables ; and repeating 36 syllables 



LEAENING 



107 



55 times involves pronouncing 1,980 syllables. If 
we plot these values graphically, we find they lie 
approximately on a straight line. (Figure 23). 



800 



§ 



1 

s-eoo 

1 

^400 

1 

^200 



I 



10 
LENGTH OF SER/ES 



20 



30 



Figure 23. the same results are shown as in figure 22, but are 
represented in terms op the actual amount of work done in 
order to learn the series of various lengths. except for series 

OF LESS THAN 12 SYLLABLES, THE WORK REQUIRED IS A 
LINEAR FUNCTION OF THE LENGTH OF THE SERIES 



This means that as we pass from one series to 
another, the difference in the work required for 



108 GENERAL PSYCHOLOGY 

learning is proportional to the difference in the 
lengths of the series learned. If the syllables are 
repeated at intervals of .4 seconds, or in other con- 
stant rhythm, the time consumed will be proportional 
to the number of syllables spoken. If we prepare 
series of nonsense syllables of totally different mate- 
rial and of different lengths, containing 16, 17, 18, 19, 
etc., syllables respectively, and find that 16 syllables 
are learned in 3 minutes and 17 in 3% minutes, then 
the series of 18 syllables will be learned in 4 minutes, 
the series of 19 syllables in; 4% minutes, the series of 
20 in 5 minutes, and so on. It will then take 13 min- 
utes to learn a series of 36 syllables. 

Even though it may be impossible to remember 
to-morrow what we have learned to-day, to-day's 
learning makes to-morrow's relearning easier. The 
amount of positive adaptation remaining from pre- 
vious practice may be measured by the number of 
repetitions saved when material is learned over 
again. This method of measuring retention has be- 
come known as the saving method. 

Ebbinghaus, using a number of different 16-sylla- 
ble series, repeated some 8 times, some 16, some 24, 
some 32, some 42, some 53, and some 64 times. 
Twenty-four hours after each one was practised he 
found the number of repetitions necessary for re- 
learning it. In this way he discovered that each one 
of any number of repetitions produced the same 
amount of retention as any other. It happened that, 
for the length of series used, each of the original 



LEARNING 109 

repetitions saved the next day one per cent of the 
time that would have been required if there had 
been no previous practice. Thus 8 repetitions saved 
8.1 per cent of the next day's work, 32 repetitions 
saved 32 per cent of the next day's work, and 53 repe- 
titions saved 53.9 per cent. The fatigue resulting 
from many repetitions made it impossible to carry 
the experiment beyond the point of 64 repetitions. 
Except for this, 100 repetitions would probably have 
made it possible to reproduce the series the next day 
without any review. It will be remembered that to 
learn a series of 16 syllables, so that it may be re- 
peated once without error immediately after the 
learning, requires about 30 repetitions. Figure 24 
shows the relation between the first day's practice 
and the next day's relearning. 

FoKGETTING 

If a given amount of material is memorized, we 
may measure the amount retained in memory at any 
later time by finding the length of time that is re- 
quired to relearn the material. The time saved in 
relearning, compared with the time required for the 
original learning, gives us a quotient that stands for 
the proportion retained in memory. By this method 
it is shown that the memory deteriorates as time 
goes on, and that the rate of deterioration is 
most rapid at the outset. This rate of forget- 
ting as measured by Ebbinghaus is shown in Figure 
25. 



110 



GENERAL PSYCHOLOGY 



Meumann and others report what they take to be a 
slight recovery of memory at the end of 24 hours. 14 
This anomaly was not shown in the careful work of 



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NUMBER OF REPEr/T/OMS 



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FlGUEE 24. THE TIME SAVED IN RELEABNING A SERIAL RESPONSE OF 16 
NONSENSE SYLLABLES SHOWN AS A FUNCTION OF THE AMOUNT OF 
YESTERDAY'S PRACTICE. THE AMOUNT OF POSITIVE ADAPTATION FOUND 
AT THE TIME OF RELEARNING IS A LINEAR FUNCTION OF THE AMOUNT 
OF WORK DONE 24 HOURS EARLIER 
(AFTER EBBINGHAUS) 

Ebbinghaus though a tendency to such recovery may 
be noticed in Figure 25. Meumann's subjects were 
unable to recall as much 9 hours after practice as 
they could recall 13 hours later. Graphically rep- 

14 Meumann, op. tit., Chapter 7, Sec. 6. 



LEARNING 



111 



resented, there was a rise in the forgetting curve 
between the 9- and the 24-hour points. Many suppo- 



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FlGUEE 25. THE BATE OF FORGETTING A NONSENSE SERIES (AFTER EB- 

BINGHAUS ) . THE AMOUNT OF POSITIVE ADAPTATION REMAINING 

AT ANY TIME IS MEASURED BY THE SAVING METHOD 



sitions have been made on the basis of these results. 
Colvin says "this improvement in memory seems to 



112 GENEEAL PSYCHOLOGY 

be due to the fact that the original impressions have 
had an opportunity to become associated with per- 
manent elements in consciousness, and, therefore, 
are capable of revival more readily after a certain 
lapse of time." 15 

From the following experiments by W. E. Wilson 
in the local laboratory an interpretation of Meu- 
mann's results in terms of the facilitating action of 
conditioning stimuli is suggested. Ten subjects 
learned lists of ten nonsense syllables, and 72 hours 
later relearned the same lists sometimes in the same 
surroundings, and sometimes in different surround- 
ings. Each subject learned one list in the labora- 
tory and relearned in the laboratory, learned a sec- 
ond list in the laboratory and relearned out of doors, 
learned a third list out of doors and relearned in the 
laboratory, and learned a fourth list out of doors and 
relearned out of doors. In eight of the ten subjects 
there was greater saving in each case where re- 
learning occurred in the same surroundings in which 
the first learning had taken place. Two subjects 
showed in one of their four series a greater saving 
where relearning had occurred under dissimilar con- 
ditions. An average of 11.4 per cent fewer repeti- 
tions were required to relearn in similar surround- 
ings. 

In another experiment the subject was seated in 
a room and copied a list of letters on a typewriter 
whose keys had been arranged in a random order. 

is Colvin, The Learning Process, p. 140. 



LEARNING 113 

He copied the same list 24 hours later and the times 
were compared. A variable condition consisting of 
the presence or absence of the odor of oil of pepper- 
mint was used. Each subject practised a list with 
the odor present and repeated the same list with 
the odor absent; he then practised a list with the 
odor present and repeated the list 24 hours later with 
the odor present. He then practised the list without 
the odor and repeated with the odor; and last prac- 
tised without the odor and repeated without the 
odor. Thirteen subjects were used, and the aver- 
age saving in the time required to repeat the list was 
9.4 per cent greater when the repetition took place 
under the condition of the first practice. 

It is highly probable that the greater retention 
shown by Meumann's subjects at the end of 24 hours 
depended upon the daily recurrence of conditioning 
stimuli. There is a diurnal rhythm of experience 
that results in a characteristic internal state at each 
hour of the day. We sleep, eat, work, and play ac- 
cording to a fairly rigid schedule. The resulting 
periodic bodily states, present at the original learn- 
ing, contribute familiar stimuli to anyone who is en- 
gaged in relearning after a 24-hour period. These 
stimuli come to condition the responses and facili- 
tate the relearning. 

Whole and Pakt Learning 

One of the practical questions that arise when we 
have something to commit to memory is whether the 



114 GENEEAL PSYCHOLOGY 

material should be rehearsed from beginning to end, 
or broken up into parts so that each part can be 
learned separately and the parts later combined. If 
the law represented by Figure 23 held for short 
series as well as for long, it would take approxi- 
mately twice the time to learn any series as to learn 
a series half that length. Part learning would then 
evidently be wasteful, because it would take the same 
time to learn by parts as to learn by wholes, and 
after the parts were learned the order of the parts 
would have to be learned also. The law (Figure 23) 
holds, however, only for lengths somewhat greater 
than the memory span. This memory span is the 
amount that can be accurately reproduced after a 
single reading. Because very small parts are mem- 
orized with relatively greater ease than large parts, 
we have no way of determining in advance of expe- 
riment whether the easy learning of small parts 
compensates for the necessity of linking these parts 
together after each has been committed to memory. 
Ebbinghaus has shown that when two series of 
different lengths are memorized to the point of one 
perfect reproduction, the longer series is better re- 
tained after 24 hours than is the shorter series. 
Thus, 33 per cent of a 12-syllable series is shown by 
the saving method to persist after the lapse of one 
day, whereas 48 per cent of a 24- syllable series is 
retained. This fact, taken in conjunction with the 
law (Figure 23) that an increase in the length of the 
series demands a corresponding increase in the 



LEARNING 115 

amount of work required for learning, gives us rea- 
son to expect that experimental results will show a 
saving when the method of learning by wholes is em- 
ployed. 

Experimental results demonstrate conclusively 
that part learning is wasteful and whole learning 
most efficient. The whole method requires less work 
for a single accurate reproduction, and for a given 
amount of work done results in fewer errors and bet- 
ter retention. This holds true for both nonsense 
material and for meaningful material. 16 

The word "learning" is here used in the sense of 
verbatim memorizing where only serial responses 
are practised. In such a subject as geometry, the 
laws of whole and part memorizing do not apply. 
This kind of learning will be considered in the chap- 
ter on perception. 

Results of the Distkibution of Peactice 

If we have a certain amount of time to spend in 
memorizing, it is found advantageous to distribute 
this time over several days rather than to utilize it 
all at one sitting. Ebbinghaus found that a 12-syl- 
lable series repeated 68 times consecutively required 
7 repetitions for relearning 24 hours later. Series of 
the same length repeated on an average of 17.5 times 



i«Lyon, op. tit.; Pechstein, Whole vs. Part Methods in Motor 
Learning, Psychological Monographs, 1917; Pyle, "Economical 
Learning," Journal of Educational Psychology, 1913, pp. 148-158; 
Pyle and Snyder, "The Most Economical Unit for Committing to 
Memory," ibid., 1911, pp. 133-142. 



116 GENERAL PSYCHOLOGY 

the first day, 12 times the second day, and 8.5 times 
the third day (38 in all as against 68) needed but 5 
repetitions for relearning on the fourth day. It is 
evident from this, and from similar results that have 
been found for meaningful material, that economy 
of learning demands distributed repetitions. 

Lashley has shown that, in training white rats to 
choose the path leading to food, using two trials a 
day saved 69 per cent of the work that would have 
been necessary if ten trials a day had been used. 17 

Learning Meaningful Material 

Learning a prose passage verbatim, committing 
verse to memory, or learning to say a set of non- 
sense syllables as in Ebbinghaus' experiments, is the 
acquisition of serial response habits. When the 
practice begins, each printed symbol is the stimulus 
for a response that has been already attached to 
this symbol by conditioning. As the stimuli occur in 
a given order, the reactions follow each other in a 
given order,, and with a sufficient number of repeti- 
tions the serial response is established independent 
of visual stimuli but dependent upon proprioceptive 
and auditory stimuli. 

In learning nonsense syllables the learner is 
wholly unaccustomed to the order of the responses, 
and the whole of the series must be learned. In deal- 



17 Lashley, "A Simple Maze ; with data on the relation of the dis- 
tribution of practice to the rate of learning," Psychobiology, 1918, 
pp. 353-367. 



LEARNING 117 

ing with words, on the other hand, the learner is 
seldom without some previous experience of their 
sequence, and when committing to memory ordinary 
prose he relies very largely upon already formed 
serial response habits. Familiarity makes relatively 
easy his remembering combinations of "sensible" 
words. The meaningfulness of language is a fur- 
ther aid to prose learning. This aid is partly com- 
posed of gesture and characteristic emotional ex- 
pression, of customary pitch, speed, and intensity 
variations of the voice. The response tendencies 
that are touched off by each of the spoken words 
also play their part in the reenforcement. 

Some prose is easy to commit to memory, whereas 
other prose is difficult. Easy prose contains stero- 
typisms and familiar word combinations. Less stu- 
pid and more original texts combine words in a less 
predictable order, and so are more difficult to memo- 
rize or even to read. Verse is easy to learn on ac- 
count of its set rhythm and its predictable end 
rhymes. 

Trial and Error 

Certain organisms, such as paramoecium, have 
for the most part but a single manner of response. 
This is given to every harmful situation the animal 
meets in its forward swimming and consists in back- 
ing, turning to one side, and then proceeding in a 
new direction. If this response brings it again into 



118 GENERAL PSYCHOLOGY 

harmful conditions, the response is repeated until 
the animal is progressing through a medium that 
contains no stimuli for this avoidance reaction. 
When an animal makes many trials, any one of which 
may or may not be specially fitted to remove the 
animal from harm or bring it into better surround- 
ings, and when as a result of these trials it finally 
stumbles upon the suitable response, its behavior is 
called trial and error. 18 

Trial and error enters into the behavior of all ani- 
mals. When hungry, they are likely to range about 
until, after many fruitless reactions, they come at 
last by chance upon food or the signs of food. In 
the same way mates are discovered, new shelter is 
found, or building materials secured. The trial and 
error behavior of most higher animals differs from 
that of the lowest forms in exhibiting not one but 
many different kinds of response. If we place a 
cat in a " puzzle box," the door of which opens only 
when the cat pulls a string or turns a knob, the cat 
will make many kinds of unsuccessful movement be- 
fore it accidentally hits upon the proper means of 
escape. 

Most inventions and discoveries are the result of 
happy accidents. Charles Lamb's hypothesis of the 
origin of roast pig is not wholly fanciful. We may 
be certain that the discovery of intoxicating bev- 
erages was due to the carelessness of some primitive 

is Thorndike, Animal Intelligence, p. 35ff; Jennings, Behavior of 
Lower Organisms. 



LEARNING 119 

housewife who allowed her fruit to spoil but whose 
frugality prompted a reluctant use of a concoction 
whose hidden possibilities must soon have had a 
wide publicity. 

A series of trial and error responses may become 
a habit in certain cases through the agency of con- 
ditioning stimuli in the manner described in the 
discussion of serial responses. It is, very seldom, 
however, that the series of trial and error responses 
as a whole becomes fixed as a habit. Usually the 
series is shortened in the process of habit formation, 
the final response being given but many of the futile 
responses that preceded it being eliminated. We 
may now ask the question how this shortening of 
the series is accomplished. 

The Shortening of a Trial and Error Series into 
a Final Habit Response 

When considering the subject of threshold of re- 
sponse we found that a stimulus may be too weak 
to elicit any movement. When a stimulus is above 
the threshold, the kind of reaction it causes may 
depend upon its intensity. It is a general principle 
that most stimuli, which when weak cause an ap- 
proach reaction, cause avoidance when they become 
very intense. This is illustrated by taste stimuli. 
The sourness of lemonade and the bitterness of 
coffee can be increased to a point where these drinks 
are avoided. A limited amount of salt is necessary 



120 GENERAL PSYCHOLOGY 

to make eggs palatable, but when exceeded causes 
avoidance. Children instinctively seek sweet food, 
but food may be so sweet as to become disgusting. 
The resistance that a little child shows to rough 
handling may be replaced by acquiescence to gentle 
manipulation. The baby accepts more readily the 
nipple of his nursing bottle when it is gently placed 
in his mouth than when it is forcibly inserted. 

The response that a new-born baby gives to a 
stimulus is definitely determined by the innate struc- 
ture of his nervous system, although there may be 
minor fluctuations of response in the same infant at 
different times due to such physiological changes as 
hunger or fatigue. His response tendencies are in 
large part predictable. He naturally responds by 
grasping, looking, withdrawing, or other movements 
according to the nature of the stimulus. Thus ap- 
proach and avoidance are not chance behavior, and 
the fact that all people learn in much the same way 
is due to their being equipped to respond to a given 
stimulus by the same reaction. Many of these re- 
actions are simple reflexes. 

The more remote an object is, the less intense is 
its stimulation, and approach to the object gradually 
increases the intensity of this stimulation. In cer- 
tain cases an intensity may be reached that causes a 
turning away. Thus the increasing stimulation of a 
single sense organ often results successively in op- 
posite orientations. 

Another frequent result of approaching an object 



LEARNING 121 

is to bring stimuli to bear upon sense organs not at 
first affected. A single object may be the source of 
stimuli first to distance receptors, such as eyes, ears, 
or nose, and later to the sense organs in the skin, 
muscles, and tendons. When a deer approaches at 
the sight of a man, not only does the visual stimulus 
increase in intensity, thus tending to make the deer 
take flight, but its greater proximity to the man 
brings into play odor stimuli, in response to which 
the deer turns away. This succession of approach 
and avoidance is characteristic of most trial and 
error behavior. 19 

The incompatibility between approach and avoid- 
ance is for the most part an incompatibility of ori- 
entations. The movements of locomotion made by 
the deer are not fundamentally different in approach 
and in retreat. The difference lies in the direction 
in which the deer is turned. This makes evident 
the importance of the analysis of movement groups 
into their component parts. 

There is a classical example of the baby and the 
candle. The baby seeing the flame approaches his 
finger, and on feeling the flame withdraws his finger. 
If charged wires are placed before the opening of 
a rat's food box, so that the animal in stepping upon 
them receives a mild punishment, his approach is 
followed by avoidance. If a bird takes a bite of a 
cinnabar caterpillar, the taste makes it reject the 

is Holmes, Studies in Animal Behavior, Chapter VII ; Watson, op. 
cit., Chapter 8. 



122 GENERAL PSYCHOLOGY 

food. A master who does not enjoy the friendly- 
greeting of the dog that places his dirty forepaws 
on clean clothing, causes the dog to desist by step- 
ping on the hind feet of the animal. In all these 
cases while the approach stimulus is still present, 
the avoidance reaction has been called forth. The 
result is that the avoidance reaction is now condi- 
tioned by the approach stimulus, so that on the next 
occasion the avoidance response tends to be given as 
soon as the approach stimulus is received. The sight 
of the flame has become the conditioning stimulus 
for withdrawing the finger. The sight of the door 
of the food box has become the conditioning stimulus 
for turning away. The sight of the caterpillar has 
become the conditioning stimulus for rejecting the 
food. The sight of the master has become the con- 
ditioning stimulus for returning to all fours. In 
addition to the conditioning visual stimuli involved 
in these responses, the proprioceptive stimuli 
brought about by the approach movements serve to 
condition the movements of withdrawal. 

It is obviously impossible for the baby to extend 
and withdraw its hand at the same time, for the rat 
simultaneously to approach and retreat from the 
door, for the bird to eat its caterpillar while reject- 
ing it, or for the dog to paw his master while back- 
ing away. The interference of these opposed move- 
ments may not, on the second occurrence of the ap- 
proach stimulus, prevent the succession of approach 
and avoidance, but eventually repetition establishes 



LEARNING 123 

the conditioned response more firmly, so that in the 
end, provided the avoidance stimulus is sufficiently 
strong, the approach response ceases to be given. 
This is due to the gradual lowering of threshold of 
the avoidance response as elicited by the approach 
stimulus and the resulting mutual inhibition of the 
two opposed response tendencies. "When this occurs, 
we say the baby is trained to avoid the candle, the 
rat to avoid the door, the bird to let the caterpillar 
alone, and the dog to proper conduct. 

Emotional reenforcement is usually associated in- 
stinctively with avoidance responses. Running away 
is accompanied by fear; rejecting food, by nausea; 
averting the eyes, by disgust or shame ; withdrawing 
the burnt hand, by grief; turning away from in- 
superable obstacles, by annoyance. The responses 
to all pain stimuli are emotionally facilitated. This 
emotional reenforcement makes avoidance relatively 
more energetic than approach, and so in the rivalry 
of two incompatible responses it is likely to prevail. 

The approach responses in mating and food-getting 
have strong emotional reinforcements. Thus, be- 
cause of appetite, these approach movements are 
often carried out to the disregard of stimuli that 
would otherwise cause withdrawal. Negative adap- 
tation to the disregarded avoidance stimuli then oc- 
curs. Within certain limits, the longer the period 
of fasting or continence, the greater is the emotional 
reenforcement and the more aggressive the approach 
movements. This, along with the fact that abortive 



124 GENERAL PSYCHOLOGY 

behavior of this sort calls out further emotional re- 
enforcement, assures the final success of food-getting 
and mating. 

Let us consider again the case of a cat placed in 
the puzzle box. After many fruitless movements he 
is attracted by the button, the turning of which opens 
the door. After the cat has been placed repeatedly 
in the box, the time required for escape becomes 
gradually less, and the fruitless movements grow 
fewer, until finally the cat's being placed in the box 
may be followed at once by the successful response 
of turning the button. 

The cat when in confinement is instinctively organ- 
ized to respond to the sight of bars, cracks, corners, 
and even solid walls by approaching and pulling and 
pushing with paws, claws, nose, and teeth. If any 
part of the box is loose, the cat has a tendency to 
continue his manipulation. He is also instinctively 
organized to turn away from these same objects 
when they offer more than a certain amount of re- 
sistance to his attack. 

The situations the cat faces in the puzzle box are 
composed, for the most part, of visual stimuli that 
attract him, followed by stimuli to his proprio- 
ceptors and sense organs of touch that repel him, 
and these two classes of stimuli are given by the 
same object. He is instinctively attracted by the 
sight of the bars, but on reaching them, especially 
if they are rigid, he is instinctively impelled to turn 
away. This turning away is due to the resistance of 



LEARNING 125 

the bars to his attempted manipulation and to his 
efforts to force his way between them. Approach 
and retreat are here original tendencies called forth 
by a single object. 

With repetition the sight of the bars becomes the 
conditioning stimulus for retreat, so that the condi- 
tioned response inhibits the original response. One 
by one the movements of approach to the various 
confining surfaces of the box are inhibited by the 
conditioned responses of retreating, until at last the 
animal is attracted by the door-opening device. The 
reason that this last movement is not inhibited is 
that the device itself never serves as the source of 
a stimulus that is instinctively avoided. Although 
the cat turns away from the button in response to 
the open door, he does so not because the button 
repels him but because the open door attracts him. 
Approaching the button and approaching the open 
door are the only approach responses that are un- 
inhibited by conditioned avoidance responses, and, 
while the door is closed, the button alone calls forth 
an uninhibited response. 

When the cat is but partially trained, he makes 
useless responses to various parts of the box. He 
always ends, however, by making the successful re- 
sponse and by escaping. As some useless responses 
are given on some occasions and others on other oc- 
casions, depending upon the cat's chance position 
in the box, the successful response, always occurring, 
is likely to be the one most practised. This may be 



126 GENERAL PSYCHOLOGY 

another factor in lowering the threshold of response 1 
to the door-opening device. 20 

Mutual inhibition of two incompatible response 
tendencies may result from other kinds of situations 
than one in which the same object furnishes both 
approach and avoidance stimuli. If a dog is tickled 
on both sides simultaneously, the usual scratch re- 
flex may be elicited from neither side. 21 

Here two approach responses serve to inhibit each 
other because the tickling of each side produces a 
contralateral extension of the hind leg, as well as 
the oscillatory scratching movements of the leg on 
the side stimulated. As both legs are actuated both, 
to scratch and to support by the bilateral stimula- 
tion, and as these movements are incompatible, there 
may result either no movement at all or, because of 
the unstable equilibrium of this system, an alterna- 
tion of scratching on the two sides. It is only this 
unstable equilibrium that makes incredible the case 
of Buridan's ass, who, the victim of balanced ap- 
proach tendencies, starved while standing between 
two stacks of hay. 

A more stable equilibrium is found where an ani- 
mal is hemmed in by avoidance stimuli. The cat 
hesitates to take to the water when pursued by a 
dog. The victim in a burning building is repelled 
by both the fire and the long drop to the street. In 



20 Smith, "The Limits of Educability in Paramoecium," Journal of 
Comparative Neurology and Psychology, 1908, p. 503. 
2i Sherrington, op cit. t p. 143. 



LEARNING 127 

daily life we are often placed between the devil and 
the deep sea. 

When trial and error behavior does not involve 
avoidance responses, many fruitless movements may 
be retained in the resulting habit. The self-educated 
bricklayer is likely to preserve many superfluous 
motions that are the results of the chance arrange- 
ment of his materials at the time he first began to 
learn the trade. If an inconveniently placed brick, 
or an awkward manner of handling his trowel, had 
always been the stimulus for an avoidance response, 
as of course it occasionally is, he would not have 
developed his unskillful and costly habit. The in- 
struction a bricklayer receives consists in verbal 
directions and criticisms that compensate for the 
absence of innate avoidance stimuli. The same is 
true of learning a golf stroke, learning to play a 
violin, or learning to sing. In social behavior the 
moral code in the absence of avoidance stimuli serves 
to inhibit acts that endanger common welfare, leav- 
ing free from interference only acts of virtue. 

The reason that such habitual serial responses as 
signing one's name, whistling a melody, or reciting 
a poem, undergo no shortening by the omission of 
responses is that these acts do not bring avoidance 
stimuli into play. 

It has been pointed out before that many acts are 
made up of movements of orientation, locomotion, 
and intervention. It is not necessary that orienta- 
tion should be complete before locomotion begins, or 



128 GENERAL PSYCHOLOGY 

that locomotion should be finished before movements 
preparatory to intervention are commenced. In 
such a practised act as picking up a book from the 
floor, we do not first turn toward the book, then 
walk to the spot, bend the body, extend the arm, 
and grasp the book, all separately. We are more 
likely to start walking as we turn, bend the body 
and extend the arm as we walk, and, while grasping 
the book, turn the body preparatory to walking 
away. 

When a number of acts form a serial response, 
one act is seldom completed before the next is be- 
gun. In this way there is an overlapping of compati- 
ble movements, orientation for the next act occur- 
ring while the movements of intervention of the last 
act are still in progress. This telescoping of one act 
with another is one of the factors in shortening the 
time of a serial response. 

Where overlapping of acts occurs, more move- 
ments are made at the same time, and so more move- 
ment-produced conditioning stimuli are available to 
knit together the parts of the series. 

As a series of acts is repeated time and again, 
the degree of overlapping of the individual acts in- 
creases more and more, until limited by the ana- 
tomical structure of the animal or by the require- 
ments of the situation. This overlapping is made 
possible by the fact that many conditioning stimuli 
have been acting for some time before the response 
that they have come to condition has occurred. As 



LEARNING 129 

we approach a door and finally see the keyhole we 
reach for our keys. Later, because we saw the door 
while reaching for the keys, we take out our keys 
when we first come in sight of the door. Reaching 
for one's keys having been established as a response 
to the sight of the door, may occur while opening the 
gate, provided the door is in view. Thus the re- 
sponse may next be conditioned by the gate opening, 
and later still by the sight of the gate in the distance. 

In the same way, because of the overlapping of 
the parts of situations, a dog first responds to the 
sight of members of the family, then to their foot- 
steps, then to the sound of the train on which they 
regularly arrive. 

Ease, grace of movement, or the facile perform- 
ance of a difficult act does not come with maturity 
alone, but requires practice. Coordinated move- 
ments are guided by stimuli in the external situation, 
or by stimuli that are movement-produced. Each 
movement is attached to its stimulus by original 
nature or by conditioning, and the proper energy 
of each movement is learned by trial and error. In 
picking up a brick we grip it sufficiently to keep it 
from slipping out of the hand, take up a posture that 
prevents our being overbalanced by the weight, and 
lift with sufficient force to raise the brick from the 
ground. In the process of learning, the brick and 
each antecedent movement furnish the conditioning 
stimuli for each part of the act. We employ a very 
different prehension, posture, and lift in picking up 



130 GENERAL PSYCHOLOGY 

a sponge. We are not conscious of this difference 
in behavior unless the object we pick up has a de- 
ceptive appearance. 

Awkwardness is eliminated by trial and error, and 
by the dropping out of incompatible movements that 
constitute mistakes. We adjust the force of mus- 
cular contractions to the work that is to be done. 
Such adjustments, together with the elimination of 
false moves and the telescoping of successive acts, 
results in a maximum simplicity of the effective re- 
sponse, and this we call coordination, or eusynergia. 

The nervous structure that governs many coordi- 
nated acts is a matter of original nature alone. 
Birds and insects fly without practice; the baby 
balances on his two feet by means of a neural 
mechanism that, though it improves with use, is an 
endowment of great effectiveness; nursing move- 
ments occur in an orderly combination and sequence. 
The extent to which the cerebral cortex is involved 
in learned coordination where the sequence of move- 
ments is independent of stimuli remains somewhat 
a matter of conjecture. It is not probable, however, 
that an elaborate series of movements may be coor- 
dinated by cortical processes independent of move- 
ment-produced stimuli. 

Imitation 

When a response resembles its stimulus, we call 
the response imitation. We laugh on hearing others 



LEARNING 131 

laugh. A fright response spreads from individual 
to individual in the herd. One sheep jumps the fence 
because the preceding sheep jumped it. The barking 
of one dog causes all the dogs of the neighborhood 
to join in. On seeing a person studying the sky we 
stop and do likewise. When a cage of pigeons is 
supplied with water, the water may not be noticed 
for some time, but when one pigeon begins to drink, 
several others will usually perform the same act. 
Smoking, yawning, whistling, throwing stones at a 
target, rising and going home, hissing and applaud- 
ing, are stimuli that readily call out imitation in 
others. 

Tickling is probably the original stimulus that 
causes a baby to smile. He does not at first smile 
by imitation, but in order to learn to imitate he 
must have someone present to smile back at him. 
If the sight of a smiling face accompanies the baby's 
act of smiling, it thereby conditions his response 
and will later cause him to smile in the absence of 
tickling. 

Practically all imitative behavior is made up of 
conditioned responses, there being very few cases of 
instinctive imitation. These few cases are prob- 
ably limited to the tendency of lower animals to 
run, swim, and fly together, to orient themselves in 
the same direction, and to follow one another. The 
instinct of following is very often the act of ap- 
proaching something that is moving away. This 
analysis applies rather to the following of fawns, 



132 GENERAL PSYCHOLOGY 

kittens, and puppies than to the following of chicks. 
In the case of the fawn that follows its mother in 
her flight the approach response is very evident, 
for when the mother stops, the fawn nestles against 
her. 

The dependence of imitation on learning is well 
illustrated by language acquisition. The baby is at 
first moved to make a great variety of vowel and 
consonant sounds by such stimuli as he receives from 
a moderately full stomach, a soft bed, and a warm, 
well lighted room. The sounds he makes accompany 
the movements that produce them and, because the 
vowels are sustained and the consonants either sus- 
tained or repeated, these sounds also precede the 
movements that continue or reiterate them. They 
thus become the conditioning stimuli for their own 
production, so that when uttered by others they are 
imitated by the baby. A period of practice, during 
which the baby plays with these sounds, is neces- 
sary before imitation is possible, and by this prac- 
tice the baby is prepared to imitate the particular 
sounds of any language. 

Imitation is seldom an exact replica of the act 
that is imitated. The imitator's response is that 
habitual act of his that most nearly resembles the 
act he observes. As a person grows older, his reac- 
tion tendencies become less variable and more stereo- 
typed. Thus a child is in many ways a better mimic 
than is an adult. If, for example, in his playing 
with sounds, a baby has familiarized himself with a 



LEARNING 133 

certain French vowel, he is likely to imitate it with 
considerable accuracy, whereas an adnlt, whose lan- 
guage responses, throughout a lifetime of practice, 
have been confined to English sounds, will imitate 
the French vowel by its nearest approximation in 
his native tongue. 

In New England the invocation, li O mihi beate 
Martine," is found in degenerate form as the ex- 
clamation, "Oh my eyes and Betty Martin." The 
baseball player in his first attempts at golf imitates 
a golf stroke inaccurately because of his familiarity 
with a bat. One of the reasons that it is hard to 
learn to dive is because we have learned so well to 
jump feet foremost The motion picture actor's 
failure to imitate the behavior of a social class to 
which he does not belong is the product of a life 
spent in acquiring a manner of quite another sort. 
The plasticity of children lies in their relative free- 
dom from stereotyped habits. The behavior of an 
adult falls. into ruts from which he extricates him- 
self only with great difficulty. 



CHAPTEE IV 

COENOTROPES 

Watson performed an experiment in which a 
baby was shown a white rat. The baby looked at 
the rat without displaying any fear. The rat was 
exhibited again, and, while the baby was looking at 
it, an iron bar was struck. The resulting noise 
caused the characteristic and instinctive fear re- 
sponse. When the rat was exhibited a third time, 
the sight of the animal called out the fear reaction. 
In this way the experimenter secured a conditioned 
response to the substituted visual stimulus. The 
baby had become afraid of rats. In similar fash- 
ion, fear could be attached to toy balloons, chrysan- 
themums, the experimenter, or to any object whose 
visual appearance had originally no power to cause 
the emotion of fear. 

No movements, except eye movements, are in- 
stinctively elicited by a visual stimulus. The baby 
is surrounded by the world of things seen, and all 
these visual stimuli are available for substitution. 
By conditioning, the sight of an object prompts the 
baby to do again what he was doing when he saw 
the object, and in time many complicated and elabo- 
rate responses are determined by what he sees. 

The avoidance movements of fear, the attack 

134 



COENOTROPES 135 

movements of rage, and the approach movements 
of love are given to visual stimuli only through 
the process of conditioning. We must learn to keep 
our distance from charged wires, dangerous ani- 
mals, stoves, falling objects, and people who sneeze. 
We must acquire the habit of striking out at aggres- 
sors who have not yet touched us, and to cry when 
dangerous objects are seen approaching. Without 
previous bodily contact, probably no sex responses 
would be given to visual stimuli. 

Babies are instinctively afraid of thunder, but 
not of lightning. When lightning accompanies the 
thunder, it takes on the power to make the baby 
afraid. Objects acquire frightfulness by being pres- 
ent during fear. 

Few people are afraid of toy balloons, but many 
are afraid of the sight of dogs. This is because few 
people have been frightened in the presence of a 
balloon, but many have been barked at or bitten 
while looking at a dog. Where loud sounds or pain 
stimuli are naturally inherent in a situation, the 
accompanying stimuli that the situation offers to 
eyes, nose, or organs of touch compel in all men 
some fear as a conditioned response. Thus there 
are fears, likes, or irritations that are shared by 
the world at large. But this is usually true only 
when the situations include a natural stimulus, 
either present or impending, to these emotional re- 
sponses. We all show fear when confronted with 
a precipice or a wild cat, although this is not an in- 



136 GENERAL PSYCHOLOGY 

stinctive response. We share with our fellows an 
ideal of feminine beauty, which is a matter of com- 
mon training. Anyone is annoyed when he sees that 
he has missed his train, although the sight of a de- 
parting train is not an original stimulus for anger. 

Equipped with fairly definite response tendencies, 
a baby is born into an orderly world. He is exposed 
to a systematic routine and a fixed sequence of situ- 
ations. Above all, the combination of stimuli resi- 
dent in such objects as his bed, his clothing, his 
tub, his mother, and his own body is almost invari- 
able. The original nature common to all babies, 
together with the inevitable environment they all 
share, develops similar habits in all children. That 
all people have not identical habits is due to individ- 
ual differences in endowment and to the peculiar- 
ities of the world that each lives in. These neu- 
rological and environmental differences are more 
likely to be noticed than the commonality of endow- 
ment and the universality of the world order, which 
latter are so commonplace that their importance is 
often underestimated. 

The habits that are produced and called out by 
common situations that everyone experiences, are 
frequently given such names as fighting instinct, 
mating instinct, hunting instinct, hoarding instinct, 
shelter-seeking instinct, maternal instinct, gregari- 
ous instinct, or instincts of curiosity, approval, 
scorn, mastery, and submission. Even in the be- 
havior of lower animals the acts described by these 



COENOTROPES 137 

terms may owe something to learning. When per- 
formed by man, they are always acquired reaction 
tendencies, though we all possess them by virtue of 
our having a common human nature that is trained 
in a common world. The extent of man's capacity 
for forming conditioned responses, which distin- 
guishes him from lower animals, is the outstand- 
ing attribute of human nature. 

Habits that men universally share are obviously 
to be distinguished from the private habits of type- 
writing, piano playing, vocations, hobbies, personal 
idiosyncrasies, and the like. There is no adequate 
term for these common habits in psychology. They 
might be called instinct-habits, common action pat- 
terns, vulgarities, primary acquirements, or com- 
mon acquisitions, but all these terms are either am- 
biguous or cumbersome and none of them is suffi- 
ciently concise to describe so important a class of 
acts. For lack of a better word we shall employ 
the term coenotropes to describe common modes of 
learned response that are the product <of original 
nature and commonly shared environment. 1 Fur- 
ther experiment may discover the integration of 
these coenotropes to be more dependent upon the 
slow maturation of innate nervous structures than 
we now have reason to suppose. 

A group of learned acts may be given a common 
name because of the similarity of the situations that 

iThe word coenotrope, pronounced seenotrope, Is derived from. 
koipSs common, and rp6iros habit. 



138 GENERAL PSYCHOLOGY 

cause them or because of the similarity of their re- 
sults, and thus very dissimilar acts may be classed 
together. The common mode of behavior known as 
" collecting' ' is made up of diverse acts whose re- 
sults show a greater resemblance than do the acts 
themselves. Head hunting and stamp collecting are 
very different, but both acts result in possessing a 
collection. The common mode of behavior known 
as "curiosity" may be illustrated by acts so dis- 
similar as peeping through a hole in a high board 
fence and buying a newspaper. All acts of curios- 
ity, however, are excited by situations that are sim- 
ilar in their make-up, so that the situation serves 
here as a basis for classification. 

Such a class name as " shaving" denotes a specific 
act that is a part of the learned equipment of many 
individuals. The characteristic use of many objects, 
such as a razor or an umbrella, constitutes a com- 
mon mode of behavior that is not made up of diverse 
acts. 

Common - Habits 

The original tendencies mentioned in the chapter 
on "Instinct" are fairly simple responses. It is 
possible that there are more elaborate acts that 
properly may be considered a part of original human 
nature. 

A baby, however, may acquire conditioned re- 
sponses immediately after birth, and the older ob- 
servers did not distinguish carefully between habit 



COENOTROPES 139 

and instinct in reporting the behavior of babies. 
As any normal child grows older we find him creep- 
ing, walking, balancing without support and with 
stationary feet, climbing, hitting, throwing, running 
in pursuit of moving objects, avoiding obstacles in 
his path, and making many other movements that 
the young of lower animals make as a result of neu- 
rological endowment. To what extent these acts in 
the human child are instinctive is largely a matter 
of surmise. The child's opportunity for establish- 
ing many of these stereotyped responses by trial 
and error learning is certainly great, and the uni- 
formity of conditions under which all children live 
makes tenable the assumption that learning is here 
an important factor. 

Spalding demonstrated that birds fly without pre- 
liminary trials, and that their awkward first at- 
tempts at flying are due to the immature condition 
of an instinctive flying mechanism. His experiment 
was to confine one set of birds so that they could not 
fly and to leave unrestrained a control group of the 
same age. When the control group had u learned' ' 
to fly successfully, the confined birds were liberated 
and were found to fly at once with all the precision 
of the others. 2 

It would be unjustified to infer by analogy that 
the child's first blundering efforts at walking are 
similarly the responses of an immature walking 
mechanism. It has been pointed out already that 

2 Preyer, Mind of the Child, Part 1, p. 239 ; Spalding, in Nature, 
vol. 12, p. 507. 



140 GENERAL PSYCHOLOGY 

man lacks in large part the elaborate instinctive 
tendencies of the lower animals. Spalding's results, 
however, should make us cautious of denying in the 
case of the baby a natural ability to walk. There 
is some evidence that this ability is a chain reflex. 
Spontaneous walking without preliminary trials has 
been occasionally reported of babies under the ob- 
servation of psychologists. 

Balancing on the feet is almost certainly an in- 
stinctive endowment, just as is balancing the head. 
Stair climbing, and many other forms of locomotion 
involving the surmounting of obstacles, are in part 
habits. 

In the absence of experimental work we must be 
content with conjecture as to how a child learns to 
throw. Grasping and releasing an object are in- 
stinctive, as are also patting movements of the arms. 
The combination of these movements may result in 
throwing any object that is held in the hand. The 
serial response so established by trial and error 
may be the beginning of a throwing habit. Skillful 
manipulation of objects and the stereotyped move- 
ments involved in transporting objects from place 
to place can not be regarded as instinctive. 

More than 95 per cent of adults are right-handed. 
It may be asked whether this is an acquisition or a 
natural tendency. Most children are trained by their 
parents to use the right hand in holding and manipu- 
lating such articles as cups, spoons, or pencils. Doll 
reports that among the feeble-minded about half 



COENOTROPES 141 

are right-handed and half are left-handed. 3 This, 
together with the facts that the feeble-minded are 
characteristically apathetic toward instruction and 
that they often occur in families where but little 
instruction is offered, suggests the possibility that 
dextrality is the result of training. Among babies 
up to the age of three weeks Watson found no pref- 
erential use of either hand in supporting the body 
weight. 

The absence of any isolated society of left-handed 
people opposes the hypothesis that right-handedness 
is wholly an acquisition. In anthropological mu- 
seums a left-hand weapon is an anomaly, although 
the Australian boomerang is usually thrown with 
the left hand. There is some evidence for the be- 
lief that among left-handed persons the regions of 
Broca and Wernicke are, contrary to the rule, com- 
monly found in the right hemisphere. If this is so, 
it might argue for an instinctive right- or left-hand- 
edness. 

Original responses of spitting out, grimacing, and 
head-turning seem to follow gustatory stimulation 
by bitter and sour substances. When sugar solu- 
tion is placed on the lips, sucking and licking result. 
Refusal to nurse when the nipple has been smeared 
with oil of amber or petroleum is reported by Kro- 
ner. 4 It is doubtful whether this is a tactile or an 

s Doll, "Anthropometry as an Aid to Mental Diagnosis/' Research 
Publication 8, Training School, Vineland, New Jersey, 1916. 

•* Peterson and Rainey, "Beginnings of Mind in the New Born," 
in the Bulletin of the Lying-in Hospital of the City of New York, 
1910. 



142 GENERAL PSYCHOLOGY 

odor response. Peterson and Rainey attribute 
grimacing, sucking movements, and restlessness to 
olfactory stimulation. 

Natural tendencies of approach and of avoidance 
are thus organized about situations of direct vital 
importance. Avoidance responses are provoked by 
noxious stimuli and by stimuli that are distinctively 
characteristic of harmful situations. Instinctive re- 
actions to restraint, loud noises, and bodily injury 
have already been described. Approach or quies- 
cence is called out by stimuli that are commonly as- 
sociated with the presence of food or with safe and 
beneficial conditions. This ambivalent equipment 
gives direction to all habit formation, and with it 
the new-born infant is ready to enter upon trial and 
error learning with considerable security. No visual 
stimulus, unless intense enough to cause injury, will 
elicit original movements of avoidance or attack. A 
baby soon learns, however, to retreat, struggle, or 
cry at sight of those objects whose contact has on 
previous occasions aroused avoidance. Conditioned 
responses of this sort soon modify the baby's origi- 
nal nature. 

When instinctive avoidance is unsuccessful in 
freeing the child from noxious stimuli, movements 
of attack are generally the instinctive result. Thus 
resistance to the intention of others is early de- 
veloped and bad temper follows upon teasing or 
upon the rough handling sometimes involved in 
dressing, bathing, or in any abrupt manipulation. 



COENOTROPES 143 

The attainment of coenotropes and of instinctive 
chain reflexes does not occur until some time after 
birth. If a ten-day old chick has never seen a hen, 
it will not follow a hen. James argues from this, 
and from similar examples, that "many instincts 
ripen at a certain age and then fade away." 5 He 
cites Spalding's account of a chick that was kept 
away from its mother for the first ten days and 
then, being replaced, showed no tendency to follow. 
It did, however, follow any person of whom it caught 
sight, having acquired this habit during the first 
few days. 

This fact should not be interpreted to mean that 
an instinct had faded away. There is, of course, 
no f ollowing-the-hen instinct. The young chick will 
follow anything, a handkerchief dragged along the 
floor, or a retreating man, dog, or hen. The young 
and inexperienced chick follows either man or hen 
to the disregard of stationary objects. The original 
tendency to follow is probably stronger than the orig- 
inal tendency to approach anything that is at rest. 
If the threshold for following a man has been low- 
ered by practice, even though the tendency to ap- 
proach the still object is similarly lowered, man- 
following may prevail over the tendency to approach 
the motionless object. As no practice has lowered 
the threshold of the hen-following response, the 
chick may well disregard the hen and busy itself 

s James, Principles of Psychology, vol. ii p. 398. 



144 GENERAL PSYCHOLOGY 

with other stimuli, the responses to which have been 
well practised. 

The response tendencies present in the new-born, 
being uninhibited by incompatible habits, may be- 
come attached to any one of a multitude of objects. 
Distracting habits once formed, however, inhibit the 
relatively sluggish instinctive response to a novel 
object, although this response might have been 
given before such incompatible habits stood in the 
way. 

The oft rehearsed man-following habit of Spald- 
ing's chick was well enough grounded to compete 
successfully with the tendencies to scratch, peck, or 
make off toward moving bugs. There being no hen- 
following habit, we may suppose that the hen, when 
later introduced, was merely powerless to compete 
for the chick's attention in the face of these distrac- 
tions. This seems more reasonable than the hy- 
pothesis of transiency of instinct. 

As with the chick, so with the child. At first one 
wet-nurse will be accepted about as readily as an- 
other, but later, when the infant has formed the 
nursing habit toward his mother, she alone is able 
to elicit energetic and contented suckling. Some- 
thing in his mouth is not the only stimulus that calls 
forth the nursing response in the practised baby. 
His mother's way of holding and talking to him, 
the shape of her breast and her general appearance 
are all conditioning stimuli that facilitate the child 's 
nursing. In the case of the strange nurse, the ab- 



COENOTROPES 145 

sence of these conditioning stimuli permits the suc- 
cess of rival movements of resistance and crying 
that tend to follow manipulation. Such movements 
are inhibited by the behavior called out by the 
mother. Once the movements of resistance and cry- 
ing have been elicited by the strange nurse, the 
characteristics in which she differs from the mother 
may condition these movements, so that the baby 
will struggle in her arms the next time, unless she 
has succeeded in getting him to nurse on the first 
occasion. We have no ground for supposing that 
mere strangeness causes resistance, except in so far 
as a strange situation may have the effect of break- 
ing up an habitual response series. 

Instincts ripen but do they fade! With his law 
of transiency of instinct in mind, James says, 
" There is a happy moment for fixing skill in draw- 
ing, for making boys collectors in natural history, 
and presently dissectors and botanists; then for 
initiating them into the harmonies of mechanics and 
the wonders of physical and chemical law. ' ' There 
is certainly a " happy moment " for teaching a child 
any habit. This, however, is probably not a "nas- 
cent period" but rather a time before antagonistic, 
incompatible, or distracting habits have been formed. 

Both Instincts and Coenoteopes Ake Common 
Modes of Behavior 

An uncritical description of instinct as the be- 
havior that is common to all men was popularized 



146 GENERAL PSYCHOLOGY 

by the contemporaries of Darwin. Although all men 
are fundamentally alike in their original structure, 
there are individual differences in instinctive en- 
dowment, and this individuality is no less instinctive 
than commonality or universally shared traits. 
Furthermore, a great deal of the behavior that is 
common to all men is undoubtedly learned. Every- 
body knows how to use a stick as a weapon, but no 
one does so instinctively. Wearing clothing is as 
universal as many of the elaborate instincts of lower 
animals, but is, of course, a learned act. The be- 
havior that is characteristic of any particular cul- 
ture, and that is not found elsewhere, can not be at- 
tributed to original structure, but should be re- 
garded as the effect of environment. 

The nest building of birds and insects, the web 
building of spiders, and the cocoon spinning of lar- 
vae are striking examples of complicated and elabo- 
rate instincts. These acts may be futile if the nor- 
mal course of events is interfered with, but the 
lower animals are not deterred by minor irregulari- 
ties of situation. Elaborate and serially combined 
responses are characteristic of their instinctive be- 
havior. On the other hand, the instinctive acts of 
man are relatively simple, but in the process of 
learning, these simple responses take on many and 
varied combinations. The more we investigate man's 
original nature the less intricate his instinctive re- 
actions appear to be. We ought probably to re- 
gard the elaborate instincts attributed to man by 



OOENOTROPES 147 

the school of William James as being for the most 
part learned acts. 

To call pugnacity, or constructiveness, or acqui- 
sitiveness, or self-preservation, or mating, an in- 
stinct is a dangerous concession to popular usage. 
Each component act as elicited by a particular situa- 
tion might better be so called, always bearing in 
mind that this series of acts is terminated by a con- 
summatory response. A complete understanding 
of behavior always involves an analysis in terms 
of stimulus-response mechanisms, and to name, for 
example, all the behavior of carnivorous animals 
that results in securing food "the" hunting instinct 
serves little purpose but to end prematurely the 
student's scientific curiosity. If we rest content 
with the description of the hunting instinct as the 
unlearned behavior of a carnivorous animal that 
results in his securing food, we certainly add noth- 
ing to anyone's information when we say that ani- 
mals secure food by means of the hunting instinct. 
Such an explanation is of the sort given by Mo- 
liere's physician when he says that opium puts one 
to sleep because it possesses a soporific property. 
If we are going to make use of "instinct" in the 
description of behavior, the terms must apply to 
specific reaction tendencies. 



148 GENERAL PSYCHOLOGY 

Play 

One of the most conspicuous instances of the 
unconsidered explanation of conduct in terms of a 
so-called instinctive tendency is the popular ex- 
planation of play. For a century past many writers 
have accounted for the whole range of play activ- 
ities in terms of a general "play impulse/ ' or "in- 
stinct to play," or "a disinclination to remain un- 
occupied.' ' This resembles the attempted explana- 
tion of acts so various as a snowball contest and 
the writing of a hostile editorial as manifestations 
of an "instinct of pugnacity." 

A short examination of play will serve to illus- 
trate the method of analysis of all coenotropic ten- 
dencies. When this has been done, the student will 
be less likely to consider pugnacity, curiosity, or 
piety as simple instincts. He should then not rest 
satisfied when told that men fight because of a com- 
bative instinct, that they investigate because of 
instinctive curiosity, or that they are religious be- 
cause of an innate religiosity. 

Compared with practical conduct, play is an in- 
complete act given in response to an incomplete 
situation. It will be remembered that a situation 
is made up of many stimuli and that an act is com- 
posed of many combined responses. The situations 
to which the young are exposed are almost always 
lacking in stimuli that are present in the situations 



COENOTROPES 149 

that confront the adult. The puppy's antagonist 
does not tear the puppy's flesh, and is otherwise 
less aggressive than the opponent of the large dog. 
The child's doll-house lacks stairways, plumbing, 
and many of the necessary parts of a real house. The 
doll itself may be so elaborated as to close its eyes 
or squeak, but it is grossly lacking in the character- 
istics of a real baby. You sit down on the rug and 
say, " Let's play that this is a boat." For play 
purposes the absence of naval architecture is as un- 
important as the absence of surrounding water. 
The next door neighbor is an Indian if he has feath- 
ers and a tomahawk, even though he lacks the blood- 
thirstiness of the actual redskin. 

Just as the play situations are limited, so are the 
acts of play correspondingly limited. The puppy 
is actuated to gentle aggression and limited retreat, 
whereas a richer situation with more intense stimuli 
would have resulted in either real fighting or flight. 
The child's doll-housekeeping is very sketchy, and 
her care of the doll is thoroughgoing only in such 
matters as hugging and spanking. The child's skill 
in handling the rug-boat would never qualify him as 
a real navigator. His assault upon the Indian next 
door is fortunately abortive, and may even be lim- 
ited to saying the word "bang." 

We are apt to say that the child fills in the gaps 
in the situation by imagination. This is often an 
unjustified interpretation by the adult, who is more 
likely than the child to notice the gaps and to inter- 



150 GENERAL PSYCHOLOGY 

pret the fairy story or to people the mud pie with 
apples. 

Not only is the local situation incomplete, but 
there is an incomplete apprehension of the larger 
situation. The cues to distant but related situations 
that occur in the limited play environment are over- 
looked. For this reason play is characterized by 
the low stimulus thresholds that are present within 
the smaller situation and that are due to the absence 
of inhibiting and facilitating effects of more distant 
situations. There is involved a disregard of incon- 
gruities, as in the theater when the background is a 
canvas drop instead of a prison wall, and when the 
orchestra pit would offer a way of easy escape for a 
real prisoner. Children at play have a high 
threshold for the summons of parents but a very low 
one for the behavior of their playmates. Thus play 
situations are more or less isolated from the world 
as a whole. The player is detached, irresponsible, 
carefree. Although this same isolation may at times 
seem to characterize serious work as well, this is 
really never so, work always being controlled by re- 
mote situations more or less suggested by present 
stimuli. Freedom from this kind of facilitating and 
inhibiting stimuli accounts for the frequent descrip- 
tion of play as activity without external compul- 
sion, or as aimless or purposeless activity. Such a 
description tacitly assumes that work requires re- 
enforcement from associated situations. 

In the nature of things children play more than 



COENOTROPES 151 

do adults. If they react at all to a limited environ- 
ment, it must be with a limited response. Play, how- 
ever, is not lacking in adult behavior. It is, of 
course, often deliberately planned. In athletic con- 
tests and games, conventional restrictions inhibit 
certain of the responses of participants, and so limit 
the situation to which the others respond. On the 
track we are not tripped up or pushed, although un- 
der more grim conditions this would be a part of the 
situation. Our opponent at tennis does not attack 
us with his racquet and our boxing partner attacks 
us only with his gloves. 

Not only is an act of play incomplete when com- 
pared with the movements involved in serious work, 
but the play act contains many movements not found 
in practical life. Probably the most conspicuous of 
these superfluous play movements is the talking 
that is nearly always a part of make-believe be- 
havior. In playing " horse' ' with a broomstick a 
child will speak to the object in a way that would be 
useless if the plaything were real. He will explain 
to the onlookers irtfaginary characteristics of his 
mount. Moreover he substitutes his own locomo- 
tion for that of the supposititious animal. The 
horse's life is crowded with a wealth of dramatic in- 
cident that no actual horse would tolerate. 

The origin of the extra movements of play is to 
be looked for first in the necessity the child faces of 
compensating for the sketchiness of his playthings. 
If the horse is unable to pull the child, the child 



152 GENERAL PSYCHOLOGY 

must pull the horse. The absence of temper in the 
wooden animal is made up for by much jerking, 
shaking, and clinging on the part of the rider. 
Other sources of superfluous movement are emo- 
tional expression, the traditional way of playing 
such and such a game, and the habits the child has 
formed in somewhat similar situations. 

Just as play acts contain superfluous movements, 
so the play situations contain many elements not 
found in the practical world. This is so because the 
child is obliged to use make-shift toys and to look 
for adventure under restricting circumstances. 
The tail of the broomstick horse is made of straw. 
Its travels carry it over rugs, through hallways, and 
up the stairs. Its existence is spent in an incongru- 
ous world and may at any time come to an end when 
sweeping begins. 

In play consummatory responses are never suc- 
cessfully expressed. Tea is drunk from empty cups. 
The slaughtered enemy is soon back in the fight. 
Kissing games are supervised by adult chaperones. 
In short, play is the prolongation of preparatory re- 
sponses, the consummatory response never being 
sufficiently complete to terminate the behavior. Par- 
tial responses to incomplete sex situations occur 
from earliest infancy. Before the baby is able to 
carry on a successful fight he shows anger, and 
fear is manifest before he has developed the move- 
ments necessary to flight. The incompleteness of 
consummatory responses in play maintains the pre- 



COENOTROPES 153 

current responses and produces a high pitch of emo- 
tional excitement. 

The energy with which play activities are carried 
on suggests at once their reenforcement from inter- 
nal responses such as are present in the preparatory 
acts of hunger, love, rage, and fear. With the be- 
ginning of play any lassitude that may have been 
evident disappears. In dancing, boxing, and the 
game of hide-and-seek the complete response is 
aborted. With the proper additions to the situa- 
tions the excitement of play may be increased to 
the point of actual love, rage, or fear. 

It follows from what has been said that play can 
not be described as a specific instinct, nor is there 
any group of original response tendencies that in 
themselves constitute play. Play is almost as much 
dependent on learning, the fixation of habits, and 
the organization of responses about objects and 
situations as are the serious activities of adult life. 

Other Examples of Common Modes of Behavior 

It is not practicable to undertake a discussion of 
all coenotropes because of their great number, and 
because many of them are relatively unimportant. 
The student must acquire the ability to analyze the 
many common modes of action that have class names 
in common speech, and to distinguish the parts 
played by original nature and by learning. Fear 
of strangers, homesickness, fear of the dark, and 



154 GENEEAL PSYCHOLOGY 

curiosity will serve as representatives of the many 
coenotropes that are ordinarily recognized. 

No baby shows a fear of strangers until he has 
developed many habitual responses toward his fam- 
ily. These habitual responses are called out in 
fairly definite order by such stimuli as his mother's 
appearance and the way in which she acts. He 
comes to adjust his responses to his mother's next 
move, and if she behaves in an unusual way, his 
serial response is disrupted, with the result that he 
is likely to cry. Since the performance of any serial 
habit response depends upon receiving the proper 
stimulus for each step in the series, the absence of 
any one of these usual stimuli, or the presence of 
any stimulus provoking an incompatible response, 
will result in blocking the serial reaction. The 
blocking of any habit series results in emotional 
arousal. 

When a stranger holds out his arms to a baby, the 
baby may respond to this familiar situation by "go- 
ing" to the stranger. Further intercourse with the 
stranger, however, does not yield those stimuli on 
which the baby's intercourse with his mother is 
based. His chain responses are thus disrupted and 
he cries. If his mother is standing by, the sight 
of her will cause him to reach out toward her and 
thus be taken from the stranger's arms. If the 
stranger wears unfamiliar glasses, beard, or cloth- 
ing, other strangers of like appearance will be 
feared when met. If the mother is by custom more 



COENOTROPES 155 

polite to strangers than she is to members of her 
immediate family, her manner toward guests may 
become the cue to shyness in the child. 

Homesickness is similarly the result of the dis- 
rupting of serial response tendencies caused by the 
absence of necessary and familiar stimuli. The 
child in a strange situation is prompted to begin 
many acts that can not be carried out. Anyone is 
ill at ease when his habits do not run smoothly. In 
a foreign country his speech fails to alter his en- 
vironment in the way that is compatible with his 
habits, and homesickness results. A letter from 
home starts behavior that can not be consummated 
in strange surroundings, and he shows depression. 
People whose routine involves the presence of others 
are subject to loneliness when in solitude. 

Darkness is not an original stimulus to fear, but 
there are many factors that contribute toward the 
commonality of fear of darkness. One of these fac- 
tors is the disruption of responses dependent upon 
visual stimuli. Our progress across the room is 
ordinarily determined by what we see. In the dark, 
the serial response is disorganized. Moreover, pre- 
vious injuries from violent contact with objects in 
a dark room have left us with conditioned responses 
of avoidance and grief to darkness as a substituted 
stimulus. The likelihood of fear is further increased 
by the fact that when the light is turned out, we 
are no longer distracted by what we see, and there 
is less interference with the instinctive tendency 



156 GENERAL PSYCHOLOGY 

to be frightened at the many sounds that are every- 
where present. To these direct causes for the de- 
velopment of a common fear of darkness is added 
the observed effect of darkness upon our fellows. 

Curiosity is not a specific act, but acts of curios- 
ity may be distinguished as a class. All such acts 
are the result of a blocking of responses that are 
called out by partly unfamiliar situations, and such 
behavior is always accompanied by emotional drive. 
Our tendency to enter the dark cave is blocked by 
fear of the wild animal that might inhabit it. If 
the interior of the cave is familiar to us, we feel 
no curiosity. Conversely, no unfamiliar object 
arouses curiosity unless some element of the situa- 
tion hinders further acquaintance. Zest is added 
to the performance of any act by reason of its be- 
ing prohibited. The scientific curiosity of a gen- 
eration ago concerning biology was in part brought 
about by the condemnation of the theory of evolu- 
tion. Sex curiosity is much enhanced by social 
taboo. The emotional drive present in curiosity is 
often the ordinary accompaniment of the act that is 
blocked, but is always augmented by the difficulty 
of carrying out the act. Fear, love, anger, or vari- 
ous mixtures of exciting emotion may always be 
recognized in curiosity. The classification of acts 
as instances of curiosity is based upon the presence 
of this emotional drive, upon the hindrance in the 
face of which the act must be carried out, and upon 
the novelty of the situation receiving attention. Ex- 



COENOTROPES 157 

cept in this setting, no specific act is an example of 
curiosity. 

No matter how much man modifies his conditions 
of life, the human nature of babies remains the same; 
and though man may build up elaborate machinery 
of law and custom for controlling his natural ten- 
dencies, in the race these original tendencies remain 
the constant and fundamental determiners of be- 
havior. 



CHAPTER V 



PERCEPTION 



A single object, such as a banana, may furnish 
stimuli to eyes, ears, nose, tongue, skin, muscles, or 
to sense organs in the enteric tract, but not all these 
stimuli affect us at the same time. 

A watch lies on the table. On receiving visual 
stimuli from a portion of the surface of the watch, 
we may pick it up and receive cutaneous and kin- 
aesthetic stimuli, turn it over and see the other side, 
or carry it to the ear and hear it tick. It is in the 
nature of objects that they embody this assemblage 
of diverse stimuli. 

In the beginning, our responses to watches or to 
bananas are merely reflexes to the separate stimuli 
those objects furnish. While we respond to con- 
tact with the object, other stimuli from the same ob- 
ject frequently act upon us. While seeing an ob- 
ject, we may also smell it. While smelling it, we 
may also hear it. Thus, each stimulus may finally 
call forth, by conditioning, any of the responses 
that any of the other stimuli would naturally pro- 
voke. In this sense we may say that an adult re- 
sponds to an object as a whole. After experiencing 
together the various stimuli emanating from an ob- 

158 



PERCEPTION 159 

ject, we react in a way that anticipates stimuli that 
the object is likely soon to furnish. 

A baby finally learns to avoid bodily contact with 
fire, barking dogs, whirling machinery, and wet paint 
merely upon seeing them at a distance, although the 
visual appearance of these objects calls forth no 
original avoidance responses. He learns to smile 
at sight of his mother who has cuddled him, to cry 
at the touch of a lifting rod, and to support his 
nursing bottle with his two hands when the nipple 
is placed in his mouth. All these acts are condi- 
tioned responses to substituted stimuli, and the 
formation of such conditioned responses constitutes 
acquaintance with the objects. 

When, by this process of conditioning, any stim- 
ulus from the object furnishes a cue for the early 
occurrence of responses that were originally given 
only as the result of further acquaintance, the baby 
is said to perceive the object. 

It is in the process of manipulating or merely 
observing a thing that the baby receives simultane- 
ously the various stimuli that are resident in it. 
His response to any one of these stimuli may then 
become attached to any other. In his behavior to- 
wards any object such as a chair, a pin, a stick of 
candy, or his own hand, some of these responses 
tend to become dominant and are attached by con- 
ditioning to many of the minor stimuli with which 
the object provides the baby. 

Thus objects come to "look" heavy, hot, smooth, 



160 GENERAL PSYCHOLOGY 

wet, or soft. Things " sound' 9 large, thin, distant, 
or as though in rapid motion. By touch or odor 
objects may be identified. 

The stimuli offered by an object may be materially 
altered as a result of the baby's intervention, loco- 
motion, or orientation. If he tears or crumples 
paper, it makes a noise and takes on a different 
visual appearance. If he grasps a pin, it may prick 
his finger. If he inverts the inkstand, the ink is 
spilled. If he pushes a tumbler off the table, it 
falls and crashes. If he releases his rattle, it may 
tumble off the bed. These changes in the form or 
the position of the objects occasion new responses, 
which, by conditioning, are later called out by any 
cue the object furnishes. 

A part of our environment is always changing. 
"We must learn to look out for danger and to take 
advantage of fortunate opportunities. Moving ob- 
jects alter the stimulation they give us although 
we remain quiet. Animals, guns, matches, and en- 
gines have their own peculiar ways of behaving in 
response to our manipulations, and the baby's grow- 
ing perception of such objects as these includes 
many anticipating responses dependent on past en- 
counters. A firecracker never looks the same to the 
baby after one has exploded in his fingers. The 
baby ceases to use the cat's tail as a handle after he 
has once picked up an aggressive cat in this way. 
He learns to bounce his ball, to tease his parents, 
and to coerce younger children. When this learn- 



PERCEPTION 161 

ing has occurred, we say that he perceives the ball 
as something that bounces, parents and companions 
as individuals who may be imposed upon. 

Situations recur time after time in orderly group- 
ing and sequence. The frequent reiteration of re- 
sponses to these recurring events enables us to per- 
ceive a situation as one that is about to be followed 
by its familiar consequences. Our ability to do this 
is dependent upon the overlapping of the parts of 
situations, which permits the formation of condi- 
tioned responses. The change from one situation 
to the next is always a partial change, and any two 
successive events have elements in common. 

There is then, on the one hand, perception of ob- 
jects with their groupings of available stimuli, and, 
on the other hand, the perception of events with 
their temporal sequence of stimuli. Perceptions can 
not be sharply divided into these two classes, but 
any perception may be characterized as a percep- 
tion chiefly of things or chiefly of occurrences. 

Perception is always a reaction tendency more 
or less completely expressed. When less complete, 
the expression is often limited to an orientation of 
receptors and effectors, but the neurological changes 
that go unobserved are often far reaching. Thus a 
perception that is apparently limited to orienta- 
tion may be a very extensive process in the central 
nervous system. As a result of our observing a 
thing, the thresholds of many other responses are 
raised or lowered. When we glance at the articles 



162 GENERAL PSYCHOLOGY 

in a shop window or hear it said that the bank closes 
to-day at twelve o'clock, delayed reactions are ini- 
tiated that are brought to pass only upon further 
stimulation, or in conjunction with other responses 
not yet aroused. In this way reaction tendencies are 
altered by stimuli that are merely observed, and to 
which at the time we give no overt response. We 
may sit inertly on the shore and watch people swim- 
ming, and it may seem to an onlooker that but few 
responses are involved in our perception. The next 
day, however, we bring a swimming suit to the beach 
and it is then evident that many changes occurred 
in our nervous structure as a result of the situa- 
tion that, when operating, was only "observed." 
An immediate overt reaction to objects is much less 
frequent than is the act of observation. 

Perception and Speech 

Perceptions involving a verbal response consti- 
tute a most important class, and such responses 
often serve to drain much of the energy that situa- 
tions arouse. Our interest in a distant object is 
often terminated as soon as we are able to name it. 

The expression of word perceptions is usually sub- 
vocal. Verbal symbols serve as cues for many sub- 
sequent acts. An object named is often an object 
with which we are in a better position to deal, be- 
cause much appropriate behavior is attached to 
words by conditioning. Once we have said "Good- 



PERCEPTION 163 

by" there is little to do but to go away. Before 
we call a man a thief we are less aggressive in our 
antagonism toward him than we are after the word 
has been used. 

The subvocal expression of word response ten- 
dencies is an essential part of thinking. Perception 
in verbal terms initiates new word reactions, and 
by the series of word responses our conduct is 
guided. 

Such subvocal responses consist in slight contrac- 
tion of muscles which, if stimulation were more in- 
tense or inhibitions were absent, would result in 
actual speech. We may often see fellow passengers 
on the street-car moving their lips in a manner ap- 
propriate to the words they are reading, and we can 
readily observe slight movements of our own vocal 
apparatus that are minimal movements of speech, 
even though these could not be detected by others. 

Such minimal responses are not confined to speech. 
Many of the onlookers at a boxing contest may be 
seen to follow the contest with minimal defense and 
attack movements, and in the theater audience there 
are many who shrug their shoulders with the heroine 
and become stern when the villain is confronted by 
the hero. These movements are sometimes mimetic, 
but that they are not regularly so is shown by the 
fact that they often anticipate the movement of the 
boxer or of the actor, and are the onlooker's response 
to the antagonist's threatened blow or to the vil- 
lain's advances. 



164 GENEEAL PSYCHOLOGY 

These minimal movements constitute in part the 
perception of situations, and, since they themselves 
offer proprioceptive stimulation, such movements 
may be the cues for further responses. The clenched 
fist as well as the muttered epithet plays a part in 
determining subsequent action. 

Talking is a serial response. Many of our sen- 
tences are faithfully reproduced habits that have 
been uttered in the same form hundreds of times. 
These stereotyped sentences are often imitation of 
other people's speech. In spite of stereotypisms, we 
frequently use a novel combination of words. This 
is made possible by the fact that any word, when 
spoken, is a stimulus that arouses a number of word 
reaction tendencies, because nearly any word has in 
previous speech been followed now by one word and 
now by another. Although various sequences of 
words are available, the response thresholds at the 
moment determine what sequence shall occur. 

When we use the word " abate,' ' there is little 
doubt but that this will be followed by the word 
" nuisance." But such words as "eat," " carry," 
"push," or "find" have been followed in the past 
by so great a variety of word responses that it is 
hard to predict which of the reaction tendencies pres- 
ent will prevail. 

The low threshold of the word that does prevail 
is determined by many things. First of all there is 
the influence of words uttered shortly before by 
either speaker or listener. Many of the words we 



PERCEPTION 165 

use when talking about football have been used on 
previous occasions after the term "football" has 
been introduced. 

An intelligent person in good health holds to the 
topic of conversation. One of the symptoms in in- 
sanity is an undirected verbosity in which the tend- 
ency to adhere to the topic of conversation is lost, 
and in which the words occur without regard to con- 
text. This sort of speech has been well called "word 
salad." It is often approximated by simple-minded 
and excitable people. 

In addition to the influence of verbal context there 
is the influence of non-verbal situations in determin- 
ing our choice of words. The facial expression of 
our hearer, the fact that he is a man rather than a 
woman, being in another's house rather than in our 
own, and having a good appetite instead of having 
just satisfied it, are matters that determine the 
words we say. 

Among the topics most tenaciously adhered to in 
conversation are diet, romance, and adventure. The 
drive toward this form of conversation is provided 
by the visceral organization of man, and needs but 
little stimulation from external conditions. 

Most important of all in determining the form of 
our sentences is the previous non-verbal perception 
of the objects or of the events we discuss. Past 
events dictate the words we use in their description, 
as these words are in part delayed responses to the 
described events. 



166 GENERAL PSYCHOLOGY 

The internal emotional responses play an impor- 
tant role in perception. Just as things may "look" 
hard, so they may "look" dangerous, disgusting, 
beautiful, or annoying. If the response threshold is 
high, or if the provocation is slight, the expression 
of the emotional response tendency may go no far- 
ther than these internal changes. As a result of 
stronger stimulation and reenforcement, overt emo- 
tional responses may result. 

At Diffekent Times a Situation May Prompt Us to 
Different Perceptions 

The form of any perception is determined in part 
by the combination of stimuli that affects the sense 
organs at the time, and in part by the conditioned re- 
sponses that the individual has previously associated 
with these stimuli. The threshold of these condi- 
tioned responses varies in a single individual ac- 
cording to the recency with which the responses have 
been performed, and according to the nature of the 
behavior in which he has just been engaged. The 
alignment of pieces on a chess board is perceived 
most thoroughly by a player who is in practice. A 
page of Virgil may be almost meaningless to a per- 
son who has for years neglected his Latin. Such a 
recent experience as reading a detective story may 
lower our threshold of perception of burglars. Hav- 
ing run out of gasoline the day before lowers the 
threshold of perception of the indicator of the gas 



PERCEPTION 167 

tank. After an accident on the road the driver's 
perception of traffic is changed. 

Due to the dependence of perception on habit, the 
same combination of stimuli will be perceived dif- 
ferently by two persons. The tea taster's percep- 
tion of tea, the florist 's perception of roses, the fan- 
cier 's perception of dogs, and the entomologist's 
perception of bugs, differ from the corresponding 
perceptions of untrained persons. Each of us has 
his private equipment of habit and perceives any 
situation accordingly. 

Because response thresholds vary from time to 
time, a combination of stimuli may be perceived now 
in one way and now in another. The words "time 
flies" may be perceived as a statement that time is 
fleeting or as a request to determine the rapidity 
with which flies fly. The staircase figure (Figure 
26) may be perceived as a flight of steps seen either 
from above or from below. Stimuli that may lead to 
either of two radically different perceptions are 
called equivocal stimuli. Where two diverse situa- 
tions have several elements in common, these sev- 
eral elements occurring alone as stimuli may lead to 
a perception of either situation. 

Equivocal stimuli often give rise to false percep- 
tions, which may be rectified by further acquaintance 
with the situation. Such a false perception is called 
an illusion. Reacting to a piece of tin foil seen on 
the street as though it were a coin, responding to a 
bit of floating dust in the air as though it were a 



168 GENEEAL PSYCHOLOGY 

house moth, running away from the sound of a fall- 
ing object in the woods as though it were a wild ani- 
mal, appropriating another person's umbrella under 
the impression that it is one's own, are all examples 
of illusion. 




Figure 26. staircase figure, this may be seen as a flight of 
stairs viewed from above, or as a flight 
viewed from below 



An hallucination is a response tendency, not ini- 
tiated by sensory stimuli, which follows a sensory 
impulse originating in some part of the nervous sys- 
tem. It is often the result of degenerative processes 
accompanying nervous disease, but frequently oc- 
curs in healthy individuals. All hallucinations con- 



PERCEPTION 



169 



form to reaction tendencies of low threshold. The 
insane patient who reports that he hears voices 
warning him of the treachery of an acquaintance 
must previously have acquired reaction tendencies 
of suspicion toward the person in question. 

Changes in the sense organs themselves, incident 
upon circulation and upon metabolism in general, 
provide for the normal individual sufficient sensory 
cues for hallucinations of a simple sort. This is 
most likely to occur when he is in a half -waking state 



Figure 27. the face that is perceived as nearest the observer 
may also be perceived as the most distant 



and partially isolated from sensory stimuli. It is 
of common occurrence for a person to report that his 
name has been spoken just as he is about to go to 
sleep. Visions are most frequently seen in the dim 
light of bed rooms. 

Our perceptions are determined not only by the 
habits we have acquired but also by the kind and by 
the intensity of the sensory stimulation to which we 



170 GENERAL PSYCHOLOGY 

happen to be exposed. Stimuli may occur in combi- 
nations of practically unlimited diversity and no two 
situations are ever wholly identical. As two situa- 
tions, but slightly different, may cause two very dif- 
ferent perceptions, the number of possible percep- 
tions is almost unlimited. 

Compkomise Responses in Perception 

Compromise responses have already been de- 
scribed. As we walk through the woods the direc- 
tion our footsteps take is a compromise of the many 
orientation tendencies that are aroused by rocks, 
trees, and the contour of the ground. The course of 
a bird flying through the forest is determined by the 
visual stimuli from all the obstacles it must avoid. 
There seldom occurs an isolated response. Most re- 
sponses are somewhat distorted by the total behavior 
of the moment. 

Objects and events are never perceived independ- 
ently of their settings. My dollar is one thing and 
his dollar is quite another. Food at meal time fur- 
nishes a perception very different from that of food 
after dinner. Soap experienced together with towels 
and water and soap seen on a druggist's counter 
are not perceived merely as soap. A word has 
complete meaning only in its context, and we 
perceive short sentences as wholes and not as lists 
of words. 

Man is undoubtedly of all animals the best en- 



PERCEPTION 171 

dowed with neurological mechanisms for compromise 
responses. When an unfamiliar combination of 
stimuli produces a resultant reaction, the act so in- 
tegrated may become a response habit. In this way 
perceptions shift their content and grow in fitness 
and complexity as a result of the successive occur- 
rence of slightly different assemblages of stimuli. 
Each unusual occurrence in a situation leaves behind 
it a trace of compromise that becomes a part of later 
perceptions of events somewhat the same. 

Perceptions from Simultaneous Stimuli 

There is no one sense organ in the skin or muscles 
by which we perceive things as hard, soft, rough, 
smooth, wet, dry, greasy, or sticky. In comparison 
with a soft object, a hard object, when pressed upon, 
gives more intense stimulation to touch and pain 
organs and stimulates a smaller area of the skin. 
The muscles involved when we lean upon such an 
object, or when we grasp it, are often under greater 
tension than if the object were soft. 

When we draw our finger along a surface that in- 
termittently stimulates the sense organs of touch, we 
say that it is rough. When the movement stimulates 
the same organs in the muscles, but when the stimu- 
lation of the sense organs of touch is sustained and 
not intermittent, we call the surface smooth. 

Perception of wetness results from the stimulation 
of cold organs along with the stimulation involved 



172 GENERAL PSYCHOLOGY 

In the perception of smoothness. The perception of 
greasiness requires the absence of the fine vibration 
of the skin that is characteristic of drawing the hand 
over a surface free from grease. A silver spoon 
always feels more greasy than a varnished table top 
because the polished metal surface offers less fric- 
tion. Objects seem sticky when, on releasing them, 
the skin adheres somewhat to the objects and is dis- 
placed outwardly. The perception of tickling nec- 
essitates the contraction of muscles, especially those 
adjacent to the area stimulated, and always contains 
an emotional component. 

The identification of objects by skin contact and 
manipulation alone, is called stereognosis. If we 
reach behind a screen and feel an object, we can usu- 
ally tell what it is. A watch is colder and heavier 
than a pencil. The surfaces of the two objects when 
rubbed afford different stimulation to sense organs 
in the skin and muscles. As the finger follows the 
contours, the position and movement of muscles and 
joints afford a characteristic stimulation. A lack 
of resistance in the loose parts of the watch and the 
pliability of the rubber end of the pencil furnish sen- 
sory cues to the respective perceptions. 

Space Pekception" 

The perception of distance or depth, and space 
perception in general, consist either of such respon- 
ses as saying, "That house is about a mile away," 



PERCEPTION 173 

or "This table is four feet long," or of such respon- 
ses as throwing a stone at a mark, jumping from 
one spot to another, setting out to walk to a certain 
objective, reaching for an object near at hand, sit- 
ting down on a chair that seems appropriately 
placed, or they may consist of such responses as in- 
hibiting any overt reaction, or giving attention to 
objects or turning away from them according as 
their position causes one sort of stimulation or 
another. 

Visual Space Pekception 

As a stimulating object changes its distance from 
the eye there is a change in the nature of its stimu- 
lation and a change in the character of the responses 
that are instinctively given. Visual perception of 
distance or depth depends ultimately upon these two 
facts. We shall consider first the instinctive respon- 
ses of fixation, binocular accommodation, and mon- 
ocular accommodation. 

When a spot of light falls upon any part of the 
retina other than the fovea, there is an instinctive 
tendency so to move the eyeball, and possibly the 
head as well, that the light shall be brought to bear 
upon the fovea. This response is called fixation. 
It is effected by the contraction of muscles external 
to the eyeball. These muscles include the four recti 
muscles and the two oblique muscles of each eye. 
(Figure 2.) When the same object stimulates both 



174 GENERAL PSYCHOLOGY 

eyes, each eye tends to fixate. This double fixation is 
called binocular accommodation. 

A straight line extending outward from the center 
of the fovea and passing through the center of the 
lens is called the axis of vision. When binocular 
accommodation occurs for a distant object, the axes 
of vision of the two eyes are practically parallel. 
When we look at a near object, these lines of vision 
form a greater angle. The degree of convergence 
increases with the nearness of the stimulating object 
and produces muscle strain. This muscle strain af- 
fords movement-produced stimuli of varying degrees 
of intensity. The intensity and the distribution of 
this stimulation in the external eye muscles is one 
of the sensory cues to the perception of distance. 

In order that the image of a near object may be 
clearly focused on the retina, the ciliary muscle and 
the iris muscle must be contracted (see the descrip- 
tion of the eye in Chapter 1). The contraction nec- 
essary to accomplish this clearness of focus is called 
monocular accommodation. The eye at rest is ac- 
commodated for far vision. The nearer the object, 
the greater is the contraction in the circular fibres 
of the ciliary and the iris muscles, and the greater is 
the stimulation to the sense organs that are in these 
muscles and in their attachments. This varying 
stimulation serves as another sensory cue to the 
visual perception of distance. The stimulus that 
effects these instinctive movements of monocular 
accommodation is a blurred image. It is probable 



PERCEPTION 175 

that the stimuli derived from movements of binocu- 
lar accommodation also produce instinctive monocu- 
lar adjustment. 

Along with the varying degree of remoteness of 
an object there go changes of stimulation other than 
those that cause instinctive binocular and monocular 
accommodation. The nearer an object, the larger is 
its retinal image. This is a sensory cue for per- 
ceiving the distance of all objects of familiar pat- 
tern. As all the one-cent pieces we have ever seen 
have been uniformly about three-quarters of an inch 
in diameter, we have developed, through learning, 
different responses of approaching and reaching for 
pennies, according to the size of the image they cast 
on the retina. As a tuft of cotton has no uniform 
size, the size of the retinal image it casts is not very 
suggestive of its distance. 

Near objects show a clearness of detail and a 
differentiation of shadows not seen in objects that 
are far away. This difference in stimulating effect 
we learn to interpret perceptually by appropriate 
responses. The indistinctness of things far away 
is due mainly to particles in the intervening atmos- 
phere. In the clear air of Colorado distant moun- 
tains look deceptively near. Trees seen through a 
fog look larger than they really are because, being 
indistinct, they are wrongly perceived as farther 
away. Being perceived as farther away, they are 
consequently responded to as though they were 
larger trees, for larger trees farther away would 



176 GENERAL PSYCHOLOGY 

cast visual images of the size the eye receives. This 
effect is utilized in the illusion of distance that is 
secured on the stage by interposing a fish net be- 
tween the back drop and the audience. 

Far away objects have a blue appearance due to 
the polarization of sunlight by atmospheric parti- 
cles, and this provides another sensory cue for per- 
ception of depth. 

Farther objects may be partially obscured by 
nearer objects, and when so seen are perceived as 
more remote. (See Figure 28.) Due to the fact that 




FlGUBE 28. THE PEAR IS PERCEIVED AS BEHIND THE APPLE BECAUSE IT 
IS PARTIALLY HIDDEN BY THE APPLE 



most things extend upward from the ground, distant 
objects are ordinarily seen over the tops of objects 
near at hand. Thus the objects higher in the field 
of vision are likely to seem the more remote. (See 
Figure 29.) 

If a far object is fixated and the head is moved 
from side to side, intervening objects in the field of 
vision appear to move in a direction opposite to that 
of the head movement. If a near object is fixated, 



PERCEPTION 



177 



movement of the head is accompanied by the appar- 
ent movement of more distant objects in the same 
direction. When the eye is at rest, the retinal im- 
age of an object passing in the foreground shifts 
more rapidly than that of the object moving at the 
same speed in the distance. 

When walking or when riding in a train, the fixa- 
tion of near objects in the landscape must be ac- 
complished by more rapid eye movements than the 
fixation of distant objects. All these differences of 




Figure 29. objects higher in the field of vision tend to be per- 
ceived AS MORE DISTANT 



stimulation serve as sensory cues to the perception 
of depth. 

An object seen both with the right eye and with the 
left eye is seen from the two different positions, so 
that each eye views a different part of the object's 
surface. Unless it is bi-laterally symmetrical and 
of a certain regular surface without shadows, the 
images it casts upon the two retinae will be dissimi- 
lar. The nearer an object is to the eye, and the 
greater the consequent binocular convergence, the 
more dissimilar are the two retinal images. Not 
only are the two images that are cast by the same 



178 GENERAL PSYCHOLOGY 

object different, but these images are commonly 
seen by each eye against a different background. 
The degree of dissimilarity of these images, to- 
gether with the unlikeness of their backgrounds, is 
another sensory cue to the perception of depth. 

Visual space perception includes responses to ob- 
jects seen above, below, to the right, or to the left. 
The difference in stimulation that serves to distin- 
guish such perceptions from each other is twofold. 
The part of the retina stimulated is different, and, 
if fixation follows, the eye movements involved in 
fixating the stimulating object are different. These 
eye movements afford various movement-produced 
stimuli. 

Visual Pekception of Objects 

Objects give not only such stimuli as elicit space 
perception, but furnish their own characteristic pat- 
tern and color stimulation. This printed page con- 
tains words of many different patterns and the cor- 
responding image-patterns on the retina serve as 
the sensory cues for many different perceptions. As 
the page is moved away from the eye, the images 
become smaller, but we call the patterns the same. 

It is probable that the similarity of our responses 
to an object seen at different distances is due to the 
fact that an object affords a continuous stimulation 
as it moves toward us or away from us. The pattern 
of the letter H is seen in all sizes as the letter ap- 



PERCEPTION 179 

proaches the eye. His mother seen at a distance of 
three feet looks to the baby like his mother seen at a 
distance of ten feet because he has continuously 
fixated her and has maintained other responses 
toward her as she changes her position. If it were 
not for this gradual change of size of images cast by 
approaching and receding objects, it is probable that 
all visual patterns of dissimilar size would arouse 
wholly different perceptions. Due, however, to this 
sequence of stimulation, and to the overlapping of 
responses, patterns of different size often arouse 
practically the same perception. 

Because of another sequence of stimulation, pat- 
terns of dissimilar form tend to arouse similar per- 
ceptions. As our friend turns his head, he casts 
upon our retina an image of gradually changing 
shape. All this time we are acting toward him in the 
same way. For this reason the full face and the 
profile photographs of our friend seem much more 
alike to us than the full face and the profile photo- 
graphs of a stranger. As we handle a cylindrical 
tobacco can, the image of its top changes from a cir- 
cular image to an elliptical image whose smaller 
axis gradually diminishes. The degree of resem- 
blance of two patterns certainly depends in part on 
their relative position in such a temporal sequence 
of stimulation. 

Retinal stimulation from objects differs in color, 
and various combinations of color may enter into 
the retinal pattern. Certain colors are characterise 



180 GENERAL PSYCHOLOGY 

tic of particular objects and substances, and the state 
of objects is often indicated by variations in color. 
We avoid picking up the poker by the red end; we 
cease cooking food when it is sufficiently brown ; and 
we eat a red apple rather than a green one. 

Auditoky Space Pekception 

The direction of an object is roughly perceived by 
means of the ears, because when the object is not in 
the median plane, it stimulates one ear more than 
the other. The direction of a sounding object that 
is in this median plane, in front, above, or behind us, 
is perceived very inaccurately. The evidence of a 
person who testifies in court that he heard a revolver 
shot just ahead of him on a dark night should never 
be admitted, although his testimony that the shot 
came from the right may be of considerable value. 

The direction of a continuous sound may be fairly 
well located by turning the head toward the side at 
first more strongly stimulated. When the sound is 
heard equally by the two ears, the face is directed 
toward the source of the sound. The shape of the 
external ear is responsible for slight differences in 
the intensity of a sound as it comes from one direc- 
tion or another. For this reason we may have a 
meager perception of an object 's being before or be- 
hind, even when we do not move the head. 

If a familiar object emits a sound of fairly con- 
stant intensity, this intensity is a cue for perceiving 



PERCEPTION 181 

how far away the object is. Telephone bells, fog 
horns, bumble bees, alarm clocks, automobiles, and 
even footsteps, human voices, rustling leaves, and 
falling objects arouse distance perceptions accord- 
ing to the intensity of the stimulation. The inten- 
sity of a wholly unfamiliar sound would be no cue to 
the remoteness of its source. 

The echoes that are reflected from objects furnish 
a sensory aid to our perception of distance. These 
echoes are notably of assistance to the blind, who 
find it easier to avoid obstacles when they walk with 
heavy shoes on resounding pavements or when they 
tap the ground with a stick. If the reflecting surface 
is several feet away, not only the intensity and the 
direction of the echo, but the time interval between 
the original noise and its echo may assist in the dis- 
tance perception. 

Auditory Perception of Objects 

The sounds we hear about us are combinations of 
simple tones, each tone having a different pitch. A 
tone is made up of simple vibrations of a single 
rate. Its pitch depends upon the rate or frequency 
of these vibrations. Rapid vibrations are high 
pitched and slow vibrations are low pitched. Any 
complex sound may be analyzed into its pure tone 
components. When a harp string is plucked, the 
resulting note has a fundamental tone, caused by the 
string's vibrating as a whole, and a great many tones 



182 GENERAL PSYCHOLOGY 

of higher pitch (overtones) that are caused by the 
more rapid vibrations of parts of the string. A 
well made tuning fork has practically no overtones 
so that the sound it produces approximates a pure 
tone. 

Any note, such as middle C, is different when 
sounded on a piano, a, violin, a banjo, or a harp. 
This difference is called a difference of timbre, and 
is due to differences in the intensities of the various 
overtones that each instrument produces. Voices 
of men, women, and children differ in timbre and 
this is also true of the voices of individuals. 

The overtones in a musical sound have vibration 
rates that are all multiples of the vibration rate of 
the fundamental tone. A noise is made up of a 
combination of tones whose vibration rates are in 
no simple ratio. The sounds of a passing locomotive, 
of paper being crumpled, and of a slamming door, 
are complexes of tones in disorderly confusion and 
are called noises. 

The diversity of noises is due to the peculiar 
structure of the objects whose vibration causes them, 
and so each kind of object has its characteristic 
sound. These characteristic sounds serve as the 
cues for auditory perception of objects. The sounds 
of sawing, hammering, or extracting rusty nails can 
hardly be mistaken. We cjistinguish the passing 
automobile from the passing street car. The jingling 
of coins and the jingling of a bunch of keys are suffi- 
ciently different to afford different perceptions. 



PERCEPTION 183 

Sounds may shift from one fundamental pitch, 
from one intensity, or from one timbre to another. 
This shifting, as well as a certain duration and 
rhythm, is characteristic of certain objects and 
events. "Words, and vocalization in general, more 
than any other sounds, depend upon this change of 
tonal composition and this modulation of intensity 
for their effectiveness as sensory cues. 

Olfactoey Pekceptioet 

Odor stimuli are of little use as sensory cues for 
perception of the direction of the odorous object. 
This is because a change of orientation changes but 
little the intensity of odor stimulation. The gases 
that emanate from an object and that are borne on 
the wind may affect our sense organs long after 
the source of the odor has been removed. Objects 
may be seen and heard only when present, and 
changes of position modify their stimulation. Be- 
cause of this, light and sound are the best cues for 
direction perception. 

Energetic emotional responses, many of them in- 
stinctive, are given to odor stimuli. This drive re- 
sults in trial and error behavior until a more defi- 
nite spatial perception of the object is obtained 
through other senses. There is a compensation for 
the absence of odor space perception in this drive- 
aroused trial and error behavior. The odor of food 
starts the animal on its search, although it may have 



184 GENERAL PSYCHOLOGY 

no perception of where the food is. As it nears the 
food, the odor becomes more intense and the animal's 
explorations more thorough at this spot. 

A hound, crossing the trail of a fox, probably does 
not perceive by the nse of his nose alone the direc- 
tion in which the fox has gone. If he proceeds in 
the wrong direction, the trail becomes fainter, 
whereupon he is apt to turn about and follow a scent 
that becomes increasingly warmer. As he ap- 
proaches the fox, his excitement increases and this 
keeps him from turning back once he is rightly 
headed. The ability of an ant to take the right di- 
rection when placed on a trail is probably due to its 
familiarity with the surface over which it has fre- 
quently walked, and not due to any mysterious odor 
mechanism for keeping its homeward course. 

Different odors arouse different emotions and 
lower the thresholds of particular reactions. This 
is often the result of conditioning, but is sometimes 
instinctive. Kittens, before their eyes are opened, 
and without previous experience v of puppies, will 
raise the head and "spit" when a puppy is intro- 
duced into their cage. The odor of a possible mate 
causes general restlessness among most lower ani- 
mals and lowers the threshold of mating responses. 
The odor of food causes hunger and the odor of 
spoiled food causes nausea. The ant stimulated by 
a strange hive odor shows fear, and, when con- 
fronted with one of its own group that has been 
artificially perfumed with the odor of a strange hive, 



PERCEPTION 185 

shows fight. The odor of a crowd probably has a 
quieting and depressing effect upon human beings. 

The olfactory lobes in the human brain, as com- 
pared with those in the brains of most lower ani- 
mals, are relatively small, and man's odor percep- 
tions are relatively meager. Standing upon his hind 
legs, man has a wider visual horizon and less oppor- 
tunity for bringing his nose in contact with objects. 
Thus his increasing dependence upon vision seems to 
have been accompanied by a lessened dependence on 
odor perceptions. 

The poverty of man's odor perceptions is, how- 
ever, not wholly due to the lack of an adequate mech- 
anism. With careful practice a great improve- 
ment in odor perceptions is possible. Blind persons, 
tea and wine tasters, and connoisseurs in food often 
show an interesting superiority in odor discrimina- 
tion. 

The diversity of odor stimuli, their capacity for 
arousing dissimilar responses, and the many possi- 
ble combinations of these stimuli enable us to dis- 
tinguish objects with considerable accuracy by 
means of this sense. Not only individual objects 
but classes of objects as well have their characteris- 
tic odor. Things that are not seen may often be 
recognized by their scent as tobacco, cheese, frying 
bacon, coffee, or fresh bread. All marine animals 
smell somewhat alike. So do most flowers and most 
fruits. 

The compromise reactions, which grow up about 



186 GENERAL PSYCHOLOGY 

objects as a result of our responding to the various 
stimuli that they offer, become attached to the odor 
stimuli that the objects furnish, and in this way in- 
stinctive responses of one sort are often replaced 
by learned responses of quite another. The odors 
of whiskey, tobacco, cheese, and clams are distaste- 
ful to most children, but are popular among adults. 

Kinesthetic and Static Pekception 

The perception of objects from muscle-sense cues 
has already been considered. Nearly all bodily re- 
sponses are determined in part by muscle and static 
sense stimulation that results from our position and 
our movement. Without movement-produced stim- 
uli to the proprioceptors in the legs we would be 
unable to walk. Jar and displacement of muscles 
and viscera give us perceptions of being jolted, 
dropped, or carried about. 

Our perception of rotary direction is not confined 
to instinctive responses of head turning and eye 
movements. Stimulation of the semicircular canals 
brings about many learned responses that maintain 
equilibrium in such acts as dancing, boxing, or tennis 
playing. 

Touch Pekception 

The way we identify the part of the body that is 
touched needs no elaborate explanation. A percep- 



PERCEPTION 187 

tion is always a response and the stimulation of dif- 
ferently located sense organs naturally provokes 
different responses. To a touch on the palm of his 
left hand a baby responds by closing that hand. 
Pricked on the right toe, he flexes the right leg. 
Superimposed upon these instinctive movements are 
the learned responses given to objects that he sees 
in contact with his body, and that he feels in the pro- 
cess of manipulation. 

Time Pekception 

The sequence and duration of events in the exter- 
nal world are as real as the objects that the world 
contains. The common sense justification for this 
view is the fact that events keep time with each 
other. Two objects that are dropped together from 
the same height strike the ground together. Every 
time they drop the same number of seconds is ticked 
off on the watch. Bodily functions are also syn- 
chronized with external events and with each other. 
Our intestinal tract is a not inaccurate time piece, 
and we know the lunch hour by our peristalsis as well 
as by the clock. Thus we have an orderliness of 
stimulation that determines an orderliness of per- 
ceptual responses. 

The perception of duration involves some such 
response as saying to ourselves, " While we have 
been talking, the bank has probably closed for the 
day, the postman has come and gone, and the train 



188 GENEEAL PSYCHOLOGY 

on which our friends left has reached the city." We 
are assisted in this perception by knowing that the 
bank closes, the postman comes, and the train reaches 
its destination all at the same time. We wonld be 
much more certain that all these events have oc- 
curred if we were to look at our watch, but even in 
the absence of a watch we are likely to be correct in 
our perception. 

Men have learned that of all the orderly changes 
in the external world, the series of changes in the 
position of the stars with reference to fixed points 
in an observatory is the most dependable. This 
simply means that from knowing the hour angle of 
a star we can infer more concerning other events 
than from knowing the stage of completion of any 
other orderly sequence found in nature. Because 
of this we call astronomical events the most regu- 
larly recurrent and accept them as a convenient 
standard of reference. 

Our perception of time, though nearly always 
aided by periodic stimuli from orderly events in our 
environment, may be independent of these stimuli. 
It is by no means impossible to guess successfully 
the amount of time that has elapsed since we entered 
the room. The question how we do this may be 
partly answered by recalling the facts of forgetting. 

When an act has been performed once and is then 
performed again, the ease of the second performance 
depends upon the amount of time that has elapsed 
since the first. This ease of performance, or degree 



PERCEPTION 189 

of positive adaptation, attaches to reminiscences as 
well as to overt acts. When we ask ourselves how 
long we have been sitting here, we rehearse the events 
that occurred when we entered the room. This 
rehearsal involves looking at the door through which 
we entered, making minimal movements that corre- 
spond to such acts as entering, saying what was said 
at that time, or taking our seats. The amount of 
positive adaptation that exists in these acts of re- 
hearsal after any lapse of time is a cue for our per- 
ception of the length of time that has passed. Cues 
of this sort are acknowledged in popular speech by 
such words as "I remember it as though it were yes- 
terday " or "The boat has just whistled.' ' 

A yet more effective cue to our perception of dura- 
tion is our recalling the acts or events that have filled 
the time in question. Recalling events is not possi- 
ble unless there were perceptual responses when the 
events took place, and recall is a somewhat incom- 
plete repetition of these responses. 

All events that fill any period of time vary more 
or less in rate of occurrence when referred to the 
astronomical standard, but many of them are suffi- 
ciently periodic to be dependable as measures of 
time. Pulse, respiration, and the rhythm of walk- 
ing, talking, or eating are sufficiently periodic to en- 
able us to perceive time as long or short according 
as it contains more or fewer of these events. The 
recollection of many diverse events may also enter 
into our perception of time. 



190 GENERAL PSYCHOLOGY 

The increasing fatigue that results from main- 
taining a bodily posture is significant of the time 
that has elapsed since the posture was taken up. So 
also is the increasing stimulation from holding the 
breath during short intervals of close attention. An 
interval seems longer when the muscles are tense and 
the respiration and pulse are rapid. 

Judgment 

Even the simplest reflex is not given immediately 
following stimulation. There is a period of latency 
in both sense organ and muscle, and some time is re- 
quired for the nervous impulse to traverse the re- 
flex arc. Probably the shortest reflex time is .02 
second. 

If we are asked to respond to the sound of a bell 
by lifting the hand as quickly as possible, the inter- 
val between stimulus and response is found to be 
about .15 second. This is perception in its simplest 
form. 

The perception of the more complex situation that 
involves speaking the name of a familiar object ex- 
posed to view requires about .5 second. More elabo- 
rate perceptual responses to complex situations re- 
quire a still longer time. 

Perceptions of situations that contain a novel com- 
bination of stimuli have a comparatively long reac- 
tion time, and these perceptions we call judgments. 
There is no sharp distinction between slow percep- 



PERCEPTION 191 

tions and rapid judgments. The slowness that char- 
acterizes judgment may be due to any one of several 
causes. 

The simplest cause for delay is the weakness or 
meagerness of the sensory stimulation. Music heard 
faintly in the distance may not at once be recognized 
as any particular melody. Objects seen in the twi- 
light are identified with difficulty. An unfinished 
drawing may require a moment of study before we 
decide what it represents. 

In the presence of equivocal stimuli the final per- 
ception is often delayed until facilitating habits are 
brought into play. We may waken from sleep to 
find the odor of smoke in the house. No elaborate 
perception may result until it dawns on us that we 
read in last night's paper of a forest fire in the 
neighborhood. In this way a perception may be com- 
pleted as a result of the slow action of reinforce- 
ments that we already possess, and without further 
explanation of the objective situation. 

A novel combination of stimuli brings about a 
compromise response, and this response is slower 
than one that has been practised. When we meet a 
friend who has removed his mustache, our percep- 
tion is both slow and changed in character. If the 
objects surrounding the bee hive have been moved 
about, the returning bee shows excitement and takes 
a longer time to enter the hive. In driving an un- 
familiar automobile our responses are less prompt 
and necessarily modified. These responses are 



192 GENERAL PSYCHOLOGY 

changed in character because a different combination 
of neural mechanisms has been called into play by a 
new aggregation of stimuli. The lengthened time 
of responses is a result of the interference between 
the mechanisms involved. Probably no two respon- 
ses are wholly compatible, and in extreme cases the 
interference may result in mutual inhibition. 

A dog that is first trained to come when his master 
calls him may later respond to the call of a stranger, 
even though the stranger's appearance, tone of 
voice, and odor may differ from those of his master. 
The dog's response depends upon both the similarity 
and the differences between the new and the old. A 
baby that has learned to say "duck" while looking 
at the duck in his picture book is likely to disregard 
differences and to call any bird a duck. If a hat is 
sailed over the chicken yard, the chicks may run to 
cover, giving the response that is customary when a 
hawk appears. A hunting dog may be thrown into 
great excitement if his master leaves the house 
carrying a broomstick as though it were a gun. In 
all these cases the animals have responded to those 
stimuli in the new situations that are identical with 
stimuli occurring in the original situations. The new 
features may sometimes greatly modify the response 
and may sometimes be almost wholly disregarded. 
In man, and to some extent in lower animals, these 
new features commonly bring into play reaction 
tendencies that either inhibit or facilitate an habitual 
response, or that result in a compromise response. 



PERCEPTION 193 

Counterfeit money is sufficiently different from 
real money to furnish a cue for its rejection. 
A stranger may look almost like an acquaintance, 
but a minor dissimilarity keeps us from speaking to 
him. We may be about to claim a trunk in the bag- 
gage room until we observe some strange character- 
istic about it that causes us to search further. In 
these ways response tendencies are prevented by 
our taking note of some detail in the new situation 
that was absent when the response was learned. 

One of the laboratory guinea-pigs had in its cage 
a paste-board nest-box with an entrance on the side. 
One day it gnawed a small hole in the top of the nest- 
box and immediately afterwards, on being given a 
piece of carrot, sat down beside this hole to eat. The 
food accidentally fell through the hole into the nest- 
box and the animal made a vain effort to crawl 
through the small hole to recover the food. Through 
the hole it could see and smell both the food and the 
bedding in the interior of the box. Without repeat- 
ing the effort to get through the hole, it scrambled 
down the side, ran through the entrance, and seized 
the food. This response, though facilitated by the 
food, was of course given to the familiar bedding, 
but, because the food and bedding were adjacent, the 
movement led to the food. If the bedding had not 
been present, the food would not have been recov- 
ered. It is thus evident that attending circumstances 
are often the most important factors in guiding the 
animal to a consummatory response. 



194 GENERAL PSYCHOLOGY 

Judgments are influenced by temporary reaction 
tendencies persisting from recent behavior. Going 
to a funeral distorts our sense of humor for some 
time afterward. The sentence a magistrate imposes 
on a criminal is often partly determined by circum- 
stances attending the previous case. The physi- 
cian's diagnosis is nearly always colored by what he 
has discovered concerning other patients recently 
seen. 

We often have a tendency to action in the absence 
of the object whose manipulation constitutes the act. 
While dressing for dinner, a man may discover that 
he is without a collar button. If neither shops nor 
friends are at hand, and if he is a person of intelli- 
gence, he looks about him for a substitute article 
with which to fasten his collar. None of the objects 
that his eye falls upon may seem suitable to him un- 
til finally he discovers a paper clip, which he fashions 
into a button. The perception of an object as some- 
thing that will serve our purpose is a form of judg- 
ment that may attain considerable subtilty. The 
perception of an act as the right thing to do is a 
judgment of much the same kind, and successful 
judgments of this sort characterize the highest de- 
velopment of behavior. 

A judgment may involve a choice of alternative 
responses, as when a player makes a move in chess 
or plays a certain card rather than another. We 
speak of a situation as offering a choice only when 
two or more response tendencies are approximately 



PERCEPTION 195 

equal. When the conflicting tendencies are of al- 
most equal strength, the delay in judgment is 
greatest. 

We are conspicuously lacking in judgment during 
emotional excitement, and this is because the stress 
of emotion renders unstable the equilibrium of bal- 
anced reaction tendencies. 

Judgments are often verbal. The word, which is 
itself a cue to response tendencies, is elicited by the 
situation and serves to classify the things we expe- 
rience. 

Reasoning is a series of judgments, each consecu- 
tive judgment resulting from the stimulation and 
from the neural reorganization that the preceding 
judgment produces. As a result of verbal reasoning, 
incipient action tendencies may be aroused and con- 
summated, or inhibited and drained into other re- 
sponse mechanisms. 

Conviction and Belief 

Conviction and belief may be described as the at- 
tachment of response tendencies to verbal state- 
ments that are either heard or spoken. These re- 
sponse tendencies may themselves be verbal, or they 
may be tendencies to other forms of behavior, such 
as overt acts or emotional expression. The propo- 
sition, u Toadstools are poisonous,' ' is believed when 
we refuse to eat them, when grave apprehension fol- 
lows our having eaten them by mistake, when we try 



196 GENERAL PSYCHOLOGY 

to prevent our friends from eating them, and when, 
in response to questioning, we declare that to eat 
toadstools will result in illness. When any of these 
responses is diminished or absent, we say that the 
conviction is not complete. Lower animals that 
avoid eating toadstools are not said to do so as a 
result of a conviction or a belief, because their avoid- 
ance is not conditioned upon a verbal statement. 

We are convinced of the truth of the proposition, 
"Influenza is contagious," if the tendency to say 
these words follows our discovery of a supposed in- 
fluenza case and if this verbal response makes us 
cautious. 

The moral conviction that it is wrong to play ten- 
nis on Sunday consists first of all in saying so when 
tennis is suggested. Further than this, our belief 
consists in a tendency not to play, and in displaying 
resentment toward those who do such a thing. The 
belief that debts should be paid involves advocating 
this statement, having a consequent tendency to pay 
debts, and a show of remorse when this tendency is 
prevented. When a hypocrite merely advocates this 
form of honesty and does not pay his debts and does 
not regret his failure to do so, we recognize the in- 
completeness of his belief. 

A belief may be said to be systematized when to 
alter it would involve a modification of many other 
beliefs, opinions, and habits. It is difficult for the 
West Indian Negro to give up his belief in ghosts 
because many of his convictions involve the word. 



PERCEPTION 197 

His dead friends have become ghosts; many other- 
wise inexplicable events are caused by ghosts; the 
graveyard is awful because of the presence of ghosts ; 
and the exact appearance and habits of ghosts have 
been described to him in voodoo teaching. The col- 
lege student may be slightly superstitious concern- 
ing ghosts, but, because any such belief is unsyste- 
matized, it is easily dissipated. 

When a belief that is unshared by the believer's 
associates stubbornly resists persuasive argument, 
and when it is not the ordinary result of such expe- 
riences as the believer has had, we call the belief a 
delusion. Delusions, like other opinions, may be 
systematized and emotionally reenforced, in which 
case they show an obstinate persistency. 



CHAPTER VI 

human motives 
The Delayed Reaction 

The acts we perform to-day often seem to be the 
direct result of the stimuli we received yesterday. 
We continually make plans for to-morrow and when 
the time comes we often carry out the previous day's 
intention. Is this lapse of time between the stimulus 
and the reaction a true latent period of response, or 
is the reaction, when finally given, simply a response 
to sensory memoranda furnished by our body and 
the external world? If all our sense organs were 
made anaesthetic, could we bear in mind the fact that 
in a little while we must meet an engagement or tel- 
ephone to a friend? Would any serious thinking be 
possible to a person totally deprived of sensory 
stimuli and in some way miraculously kept alive? 
Unless we find in the laboratory the answer to such 
questions as these, we are in danger of accepting 
some fanciful hypotheses as to the way in which 
thinking proceeds. 

The central nervous system, while isolated, might 
conceivably be capable of carrying on a self-con- 
tained interplay of processes that would result ulti- 
mately in an act, but the fact remains that the cen- 

198 



HUMAN MOTIVES 199 

tral nervous system never is isolated from the effect 
of constant sensory stimulation. Even in sleep and 
in surgical anaesthesia the isolation from receptors 
is only partial. 

Hunter constructed a choice-reaction box that 
had three passageways leading to food. 1 Any two 
of these passageways could be blocked and the third 
left open. The open passageway, varied at random, 
was always illuminated. By trial and error, the ani- 
mals in this box learned to select the illuminated 
opening and to avoid the others. An animal so 
trained was then placed in a release compartment 
that offered a view of all three passageways, but 
from which it could not escape until freed by the ex- 
perimenter. The light was turned on in the open 
passageway until it was observed by the animal. 
Then, after the light had been turned off, an inter- 
val was allowed to elapse before the release com- 
partment was opened. Even after this delay the 
animal could still choose the correct exit. Such be- 
havior is generally referred to as a delayed reaction. 
Hunter found that the interval between the light 
stimulus and the response could be as long as from 
1 to 5 seconds for rats, from 1 to 3 minutes for dogs, 
and more than 20 minutes for a five-year-old child. 

Rats, cats, and dogs, in order to respond success- 
fully, had to maintain their orientation throughout 
the interval. This orientation preserves the stimu- 

i Hunter, The Delayed Reaction in Animals and Children, Animal 
Behavior Monographs, 1913, No. 1. 



200 GENERAL PSYCHOLOGY 

lating effect of the proper exit until the animal is 
released. The sight of the closed barrier of the re- 
lease box inhibits the movements of escape. The 
opening of this barrier removes this inhibition, and 
furnishes a facilitating stimulus to the escape move- 
ments that the sight of the fixated passageway has 
throughout tended to initiate. The animal that 
maintains its orientation throughout the interval 
presents a picture of balanced reaction tendencies, 
each of which is excited by a persistent stimulus. 
When one of these stimuli, namely the release bar- 
rier, ceases to act, the other, the fixated passageway, 
causes a response. The situation that is here at 
work is easily analyzed. 

Children, even though they had lost their orienta- 
tion during the interval, were able to respond suc- 
cessfully. Adults do this with considerable uniform- 
ity. If the person acting as subject is carefully ob- 
served, this delay in reaction no longer seems to be 
a true latency of response. 

The response tendency toward the door last il- 
luminated would hardly have the lowest threshold 
just because of recency of excitation, as the other 
doorways may be the ones last looked at. When an 
adult subject in this experiment carefully observes 
his own behavior, one of the following factors al- 
ways seems to be present to determine his correct 
choice. Sometimes he assumes an inconspicuous 
orientation, of parts other than head or eyes, when 
he sees the light, and maintains this posture until 



HUMAN MOTIVES 201 

the interval has elapsed. This serves as his cue 
when he is released. He may guard against doing 
this, however, with some success. More frequently, 
his seeing the light in a particular doorway is fol- 
lowed by some characteristic movement reserved 
for that situation, consisting of a slight swaying of 
the body or head, slight contraction of muscles on 
one side or the other, or subvocal speech movements 
corresponding to words that designate the proper 
doorway. These minimal movements are often 
wholly unobserved by the experimenter. When the 
subject is released, a scrutiny of the doorways will 
revive one of these cue movements, which seems to 
depend upon recency and upon the emotional rein- 
forcement characteristic of all preparatory respon- 
ses, for its low threshold. This serves in turn to 
reenforce the proper orientation and approach re- 
sponses. The subject usually reports that his choice 
does not depend on having made merely the original 
orientation movements, and when his choice is cor- 
rect, he practically never fails to report the occur- 
rence of some additional cue movement, sometimes a 
series of such movements, that were begun while the 
orientation was still maintained. 

If a stimulus does not cause an immediate re- 
sponse of one sort or another, it will probably never 
cause a delayed response of any kind. If a mechan- 
ism is stimulated and the response inhibited, the 
delayed occurrence of the response, in the absence 
of the original stimulus, is due either to a mainte- 



202 GENERAL PSYCHOLOGY 

nance of orientation or to the recurrence of some 
conditioning stimulus, usually movement-produced. 
Suppose that a man is called to dinner while in 
the midst of work, and delays his response until he 
has reached a convenient place for stopping. Un- 
less he changes his posture in readiness for rising 
or maintains an uneasy tension, unless peristalsis 
jogs his memory, or unless sounds from the dining 
room remind him that dinner is in progress, his re- 
action is very likely to remain delayed until he is 
called again. If, when dinner was first announced, 
he happened to be looking at the paperweight on his 
desk as he promised to be down in a moment, a 
casual glance at the paperweight might later bring 
him to his feet. Some sensory cue seems essential 
to call out a delayed response once the original 
stimulus has ceased to act. Such a sensory cue may 
be either an organic stimulus or one external to the 
body, which, having occurred along with the origi- 
nal situation, has become a substituted stimulus for 
the delayed response. Our environment, our daily 
routine, and our rhythmical bodily functions are full 
of memoranda for these postponed reactions. Lack- 
ing these helps we would almost never carry out an 
intention. Having made an engagement for Monday 
morning we keep it because the events of Monday, 
when they occur, are different from the events of 
Sunday. No response is ever given to an abstract 
48 hours hence. A delayed reaction is not essentially 
different from any other conditioned response. 



HUMAN MOTIVES 203 

The Wish 

A wish is an emotionally facilitated tendency 
toward a consummatory response whose consumma- 
tion is delayed. This delay may be caused by the 
inhibiting action of an antagonistic mechanism when 
the situation for carrying out the reaction is pres- 
ent. Or it may be caused by the absence of the sit- 
uation necessary for carrying out an act when the 
tendency is aroused by conditioning stimuli. Pend- 
ing the consummation of an act, the opportunity for 
which is present and interference with which is ab- 
sent, the wish may be slightly in evidence while the 
act is being carried out. Thus we may wish to take 
a drink of water while preparing to do so, but this is 
only because the act of securing the water postpones 
the consummatory response. The other occasions 
on which wishing for water is evident are, first, when 
water is present and we are inhibited from drinking 
by some such circumstance as the presence of a 
thirsty friend, and, second, when a dryness of the 
throat, mention of water, or the sight of an empty 
glass prompts us to drink, and no water is to be had. 
During the delay, in either case, there is readily ap- 
parent the growing emotional reenforcement that is 
characteristic of the postponement of any consum- 
matory reaction. All wishes are consummatory re- 
sponse tendencies whose complete expression is in- 
terfered with, and whose postponement arouses emo- 
tional reenforcement. 



204 GENEKAL PSYCHOLOGY 

Attention 

The several parts of a situation do not have equal 
power at any given moment to call forth responses. 
A person gathering flowers picks some and leaves 
others, or his attention may be distracted by a lizard 
on the wall. In the theater we watch the actor and 
are oblivions of the audience. This is because of the 
differences in relative intensity of the various stim- 
uli, because of the particular orientation of our sense 
organs at any moment, because of the variation of 
conductivity in neural arcs, the result of habit and 
reenforcement, and because of fatigue. 

Attention is the orientation of sense organs to- 
ward a source of stimulation and the lowering of 
appropriate response thresholds. It always involves 
more or less preparatory innervation of the effector 
muscles. Usually associated with it is the cessation 
of most movements that do not serve to explore the 
object that is attended to. Attention is most evi- 
dent when there is a balancing of reaction tenden- 
cies toward a single object, as the orientation is then 
more persistent because the muscle contractions by 
which the orientation is maintained are emotionally 
reenforced. "When opposing orientations are called 
out by two separate objects, attention to either ob- 
ject is decreased. 

After a few seconds of attention the muscular 
adjustment of the sense organ is partly lost, but, 
because of movement-produced stimuli that this loss 



HUMAN MOTIVES 205 

occasions, the proper adjustment may be regained. 
Fatigue also occurs in the large muscle groups in- 
volved in orientation, and this has its effect upon at- 
tention. 

In addition to the fluctuation of muscular adjust- 
ment, there is a fluctuation of conductivity of the 
neural arc, probably resulting from variation in con- 
ductivity of the synapses and from the irregular 
drainage and reenforcement of the system. Thus 
we always have a sort of fluttering or pulsation in 
attention, even though careless observation may 
seem to indicate continuous attention lasting sev- 
eral minutes. 

The movements of orientation may shift from ob- 
ject to object following systematic or random 
changes in a situation. Where this shifting is pres- 
ent, there is likely to be less fatigue and more emo- 
tional reenforcement of the movements on which 
the orientation depends. Attention to one object or 
to one orderly sequence of events inhibits responses 
to unrelated stimuli, both because of the low thresh- 
olds established by the intense stimuli that result 
from a steadfast orientation and because of the facil- 
itation derived from many component responses that 
make up habitual acts. 

Volition 

A voluntary act is the outcome of a delayed reac- 
tion when reenforcement reduces a high threshold 



206 GENERAL PSYCHOLOGY 

of response or brings to an end the balancing of in- 
compatible reaction tendencies. This reenforcement 
is furnished by movement-produced stimuli and by- 
external changes in the environment. It is possible 
that the balance of tendencies might be lost and ac- 
tion result without external coercion, provided one 
of the two opposed reaction tendencies fatigues 
sooner than the other. Introspection, however, 
usually detects either a bodily change or a change of 
external stimulation as an antecedent of voluntary 
movement. 

We often overlook the external changes that affect 
our choice. We may be undecided whether to take 
the morning train for a week-end vacation. With 
opposed tendencies to action mutually inhibited, we 
delay our decision to act, but as the time grows short 
the balance is disturbed, so we pack our bag and 
start. Here it is the change in the clock that has 
destroyed the equilibrium of our hesitation, although 
we are likely to credit ourselves with having made 
an unaided choice. This disturbance of balance by 
an external event needs no lengthy discussion. A 
more interesting antecedent of voluntary movement 
is the balance-destroying stimuli that our own bodies 
provide. 

The opposed reaction tendencies that are present 
in delayed choice never leave us wholly unmoved. 
They always bring about internal responses of one 
sort or another. The energy that this opposition 
engenders is drained into other systems, and pro- 



HUMAN MOTIVES 207 

duces either slight skeletal movement or various in- 
ternal changes. Such responses provide stimuli that 
are likely to reenf orce one or the other of the bal- 
anced tendencies. If enough reenforcement is finally 
piled up on one side to destroy the balance, a volun- 
tary act results. 

Some of these internal changes are difficult to ob- 
serve except introspectively, and such a method 
never gives wholly accurate information. The res- 
piratory changes antecedent to voluntary movement 
may be graphically recorded, and serve as a good 
illustration of balance-destroying stimuli. Such a 
record is shown in Figure 30. The conditions of the 
experiment under which this and similar records 
were secured are as follows: 

The pneumograph was adjusted at the axilla level. 
The subjects selected were always untrained and 
did not suspect the purpose of the experiment. Most 
of them did not know that their respiration was be- 
ing recorded. Each of them was seated before a 
table on which were placed three small strips of 
cardboard. The following instructions were then 
given : " Wait until you feel that you wish to do so, 
then place these strips of cardboard so that they 
form some geometrical figure.' ' The time of the 
first observable movement of the subject's hand as 
he reached for the strips was indicated by the ex- 
perimenter's closing a switch. A characteristic res- 
piratory change, similar to that shown in Figure 30, 
was observed in all but one of the 12 subjects em- 



208 



GENERAL PSYCHOLOGY 



ployed. These movements consisted of a deep ex- 
piration and an inspiration that was interrupted 
by one or more periods of apnoea. The initial hand 
movement was executed only after the apnoea had 
continued for a brief moment. If the reader, pre- 



BEGfN 



END 




Figure 30. respiratory antecedents of voluntary movement, 
the procedure is described in the text. voluntary hand move- 
ments occurred at the points marked a on the time line. time 
is indicated in 5 second intervals. the figure is traced from 
the kymograph record. apnoea, following deep expira- 
tion, precedes the voluntary movements 

ferably with eyes closed, will repeat for himself these 
respiratory movements, exhaling deeply and inter- 
rupting his inspiration by several periods of hold- 
ing the breath, he will be conscious of a generalized 
innervation especially affecting the muscles that ex- 



HUMAN MOTIVES 209 

tend the arms. It is easy to see how this stimula- 
tion from apnoea may so reenf orce the reaching-out 
tendency as to reduce sufficiently the threshold and 
bring about the act. 

Freedom of the will does not consist in our being 
able to perform either of two incompatible acts at 
a given moment, but consists rather in our ability 
to carry out an intention in the face of distractions. 
In popular speech the "strong willed ,, man is one 
whose good habits are sufficiently well established to 
triumph over temptation, but this is an ethical class- 
ification. Psychologically, the morphine addict 
shows an equal freedom of will when he disregards 
the remonstrances of friends and overcomes the ob- 
stacles placed in his way by the law. 

Intention 

When, on rounding a corner, we unintentionally 
bump into a stranger, we are unprepared to meet 
the consequences of our act. When pushing him 
out of our way intentionally, we have not only given 
the precurrent responses that lead up to this thrust- 
ing him aside, but are also prepared for defense 
against his possible aggression. Intention, like the 
wish, is present only when a consummatory response 
is delayed. Intention differs from the wish in that 
it involves the actual presence of precurrent re- 
sponses which, in popular speech, "commit" us to 
the consummatory response. Intention includes 



210 GENERAL PSYCHOLOGY 

" making plans/ ' which is a form of precurrent 
response. This planning for an act is not an essen- 
tial part of the wish, because in the wish there may- 
be no precurrent responses present. Planning often 
takes the form of verbal responses or modified move- 
ments of rehearsal that serve to adjust our behavior 
to meet anticipated difficulties and to facilitate the 
consummately reaction. If, in the past, we have 
carried out a consummatory response in the face of 
familiar difficulties, the total habit so formed makes 
our tendencies to carry the matter through a second 
time more an intention than a wish. 

Deive 

Having considered what kind of response is 
naturally given to each kind of stimulus, how new 
stimuli are substituted for old, how responses are 
integrated into new combinations, and how delayed 
responses are finally brought about, there remains 
the question why some acts are more persistent 
and more energetic than others, why some tenden- 
cies are imperious and some are easily discouraged. 
It is not sufficient to say that a man's tendency to 
act in a particular way is strong because he " wills' ] 
so to act. Energetic action must be a result of a 
physiological mechanism capable of releasing and 
conducting the necessary amount of nervous im- 
pulse. 

We cannot escape the hypothesis that each 



HUMAN MOTIVES 211 

stimulus-response mechanism has its store of nerv- 
ous energy, and that nervous impulses are drained 
from one mechanism to another. In this way 
energy may be borrowed, and a mechanism that so 
borrows it is said to be reenforced. Probably every 
stimulus-response mechanism is capable of action 
without reenforcement, but few mechanisms ever 
act in isolation. 

The mechanisms resulting in acts of love, fear, 
rage, hunger, pain, shame, and other emotional 
expressions are supplied with a great amount of 
latent energy. From these reservoirs many less 
energized mechanisms receive their additional drive. 

Any act becomes emotionally reenforced once it 
has been elicited along with an emotional response, 
the emotion becoming a conditioned response either 
to the stimulus that causes the simple act or to the 
movement-produced stimuli in which the act results. 

Upon the conflict of certain reaction tendencies 
there result such emotions as grief, anxiety, shame, 
and remorse. The effect of these asthenic emo- 
tions is to depress or inhibit, rather than to facili- 
tate behavior in general. These emotions usually 
arise when some event has occurred that makes it 
difficult or impossible for us to carry out an habitual 
consummatory response. When the death of a baby 
removes him from his mother's arms, the tendency 
to fondle him is still present, but can not be ex- 
pressed. If a child breaks her doll, she is left with 
a futile tendency to play with it. A man who is put 



212 GENERAL PSYCHOLOGY 

in jail is inevitably prevented from engaging in 
most of the consummatory responses of daily life. 
In all these cases grief and the depression of activity 
result. If the obstacles to action in these cases had 
not been insurmountable, rage, and not grief, would 
have been aroused and activity increased. The 
utility of discouragement and melancholy consists 
in that the victim of circumstances does not spend 
himself in vain effort. 

The internal changes involved in emotional re- 
sponses affect wide areas and bring about sustained 
stimulation to many proprioceptors. The diffuse 
nature of emotional stimulation is easily observed 
in anyone suffering from a toothache or in a person 
who is enraged or frightened. 

No form of conduct, excepting routine habit, is 
persistently engaged in unless emotionally reen- 
forced. Routine habit itself is originally estab- 
lished with the aid of a borrowed emotional drive. 
Dancing, game playing, dangerous sports, gossip, 
theater-going, controversy, and business speculation 
are energetically pursued because of the emotional 
drive the situations arouse. The approbation or 
disapprobation of our fellows furnishes to other- 
wise weak reaction tendencies an emotional facilita- 
tion without which we would never finish the day's 
work. 

Through social convention the consummatory re- 
sponses in such acts as love, rage, and fear are often 
inhibited or blocked. During a conference with a 



HUMAN MOTIVES 213 

business enemy the preparatory responses of rage 
are aroused, but the general situation inhibits kill- 
ing. With the blocking of this consummatory reac- 
tion an ever increasing amount of dammed up en- 
ergy is provided, which finds outlet not in physical 
violence but rather in attending to business with re- 
newed drive. If the competitor wins out in the busi- 
ness deal, however, this energy finds outlet in curses, 
imprecations, slander, or frequently in the fabrica- 
tion of a story that, when told to friends, serves to 
justify failure and to elicit sympathy. After an un- 
pleasant ordeal with a business superior, a man is 
likely to talk to himself on the way home, or pos- 
sibly later in the evening to find some excuse for 
disciplining the children. 

The fascination of literary fiction is produced by 
the author's postponing any description of his hero's 
consummatory responses, and by elaborating his 
preparatory responses. By such devices to secure 
suspense the reader's interest is aroused and main- 
tained. Always the dawn breaks and Scheherazade 
ceases saying her permitted say just as the hero is 
about to be discovered in his hiding place, or while he 
is still in full flight. When true love begins to run 
smoothly, the story is ended. 

Emotional reenforcement is largely responsible 
for the tenacity of certain memories of early child- 
hood. The situations thus remembered are nearly 
always exciting. Out of 700 " first memories" re- 
cently collected, more than 97 per cent were the re- 



214 GENERAL PSYCHOLOGY 

eults of highly charged emotional experiences. The 
event that leaves us unmoved is soon forgotten, and 
it is well that this is so, for an event 's importance is 
usually proportional to its emotional effect. 

Sublimation 

In the laboratory, when men and girls are work- 
ing together, much diffuse and purposeless move- 
ment may be observed, which would not occur in 
other than a coeducational university. Properly 
utilized, this additional drive may result in effective 
work. The utilization of dammed up drive for acts 
other than the consummatory reaction to which it 
would lead if uninhibited is called sublimation. 

When a person becomes apathetic toward his 
work, he is frequently not fatigued. When this is 
so, what he needs is recreation, not rest. He may 
go to the theater, visit a friend, or play a game of 
cards, and then return to his work with new enthu- 
siasm. This drive is not so much the result of rest 
as it is the outcome of recent precurrent emotional 
responses in one form or another. Thus we distin- 
guish being tired from being stale. 

In the case of children, when rage, love, or fear 
behavior is initiated but blocked, the outlet for the 
resulting drive is often in tears or laughter. Gig- 
gling is characteristic of older children under simi- 
lar conditions, and may be shown in church, in 
school, or anywhere in the presence of the opposite 



HUMAN MOTIVES 215 

sex. The theater audience laughs most heartily at 
indelicate allusions. Laughter may occur upon the 
sudden passing of danger or upon the averting of a 
quarrel. Any incongruity in a situation may cause 
a blocking of emotional response, and this is prob- 
ably why the incongruous is often whimsical. 

The sublimated drive that enables men to sur- 
mount obstacles is of various kinds. The competitor 
shows a doggedness of conduct that is not found in 
the man who has no rivals. Love makes the world 
go round. "The fear o' hell's a hangman's whip to 
haud the wretch in order.' ' Many emotional states 
are derived from the basic elements of rage, love, 
and fear. It is seldom that one of these elements is 
lacking when any ambition is pursued with great 
tenacity of purpose. 

It is necessary to recognize certain coenotropic 
tendencies that may be observed in all young chil- 
dren. Children seek opportunities to inflict pain 
on others, and this inclination is called sadism. They 
also tend in certain situations to seek painful stimuli. 
This is known as masochism. They show a propen- 
sity to exhibit their bodies and, especially from con- 
cealment, to observe the bodies of others. All these 
tendencies are undoubtedly a part of sex behavior. 
A derivative form of the tendency to cause pain to 
others is seen in bossing and bullying other chil- 
dren, in teasing and in ridiculing them, and in com- 
pelling their submission. These acts borrow the 
drive of the behavior from which they originate. 



216 GENERAL PSYCHOLOGY 

Submitting to coercion may be developed from the 
more original tendency to seek pain. To be con- 
spicuous in any way, as when wearing unusual 
clothes or occupying the center of the stage, may be 
a modification of the tendency to exhibit the body. 

As the child grows older, his masterful, submis- 
sive, and exhibitionary tendencies conform more and 
more to the requirements of this world, and the 
origin of these tendencies is obscured. Sadism plays 
its part in taking people to prize fights, in causing 
them to read newspaper atrocities or to punish chil- 
dren, and in a more useful form the same motive 
gives drive to the physician, the magistrate, or the 
army officer. "Willingness to submit to pain makes 
men tolerant of the imposition practised on them 
by those they love. Derived from exhibitionism are 
the acts of having one's picture taken, seeking news- 
paper publicity, wearing lodge regalia, crusading for 
dress reforms, speaking in public, or running for po- 
litical office. 

Conflict 

The blocking of a consummatory response ten- 
dency, combined with the absence of any adequate 
outlet for the resulting emotion, is called a conflict. 
When a conflict arouses an unusual amount of un- 
liberated drive, a form of behavior known as hysteria 
may result. The symptoms of hysteria are some- 
times shown in relatively futile acts, more or less 
suggestive of the consummatory act that is so well 



HUMAN MOTIVES 217 

inhibited. Thus a mother who has lost her baby may 
lavish care upon flowers or household pets. More 
frequently, however, the hysterical symptom is an 
act that serves the same purpose as the act that is 
inhibited. For example, in Dr. Ames' case, the pa- 
tient who could not bring himself to desert his wife 
became hysterically blind and thus succeeded in be- 
ing removed from home. It should be borne in mind 
that the hysterical act or symptom is beyond the pa- 
tient's control. 

A persistent tendency to perform some useless, 
silly, or distasteful act is called in psychiatry a fixed 
or imperative idea. This is seen when a person can- 
not avoid humming to himself a haunting melody 
that has become displeasing, when the effort to in- 
hibit obscene, profane, or apparently commonplace 
words persistently fails, or when a distasteful act 
is repeatedly the final outcome of mutual inhibition. 
The reenforcement that makes such acts imperative 
is usually a proprioceptive mechanism, such as sex 
or anger, which has become linked up with the origi- 
nal action system through conditioning. The fear 
that results from a person's imagining that he is 
becoming insane serves as such a reenforcement, and 
by frequent use the fear of insanity increasingly oc- 
cupies the mind. When the reenforced act is use- 
ful, and not displeasing to the subject, its frequent 
occurrence causes no anxiety and is never thought 
morbid, although the drive mechanism may be the 
same as in the case of a fixed idea. 



218 GENEEAL PSYCHOLOGY 

Forgetting an act may sometimes be due in part 
to the inhibition of tendencies with which the act 
has become associated. 2 Our failure to remember 
the name of an acquaintance may be the simple re- 
sult of long disuse, but if speaking the name has be- 
come associated with inhibited action tendencies, the 
word threshold is further raised and we are often 
powerless to recall the word. 

Dreams correspond to reaction tendencies that are 
commonly inhibited in waking life. In sleep the in- 
hibitions are partly removed by the absence of cer- 
tain sensory stimuli that affect us when awake. Ee- 
sponses are prevented by the resistance in motor 
conduction paths. 

Undirected by any very rich sensory experience, 
and partly rid of inhibitions, the imagery of dreams 
follows the course of wish fulfillment in a way un- 
known to waking thought. Thus our dreams, when 
properly interpreted, reveal to us many unsuspected 
propensities. In this way dreams become useful 
material in the detection of conflicts in hysterical 
subjects. 

OVERCORRECTION" 

One of the richest sources of the stimuli that in- 
hibit our responses is the social sanction of our fel- 
lows. The world demands of us many virtues we do 
not possess. By simulating such virtues as we lack, 

2 Many instances of such forgetting are described in Freud's Psy- 
Ghopathology of Every Day Life. 



HUMAN MOTIVES 219 

and so disguising our inmost tendencies, we gain ap- 
probation and escape contempt. We ourselves, how- 
ever, are never wholly deceived by the superficial 
artifices we substitute for the more spontaneous ten- 
dencies observed in others. In our effort to con- 
form to social standards we frequently overcorrect 
for our faults, so that our virtues are too conspicu- 
ous to seem real. 

Persons who laugh loudest at the Saturday night 
bath stories are likely to have acquired punctilious 
bathing habits late in life. The genealogical bore 
is usually a man of humble origin in at least one un- 
studied line of descent. Ostentatious modesty is im- 
possible in anyone who is not immodest at heart. 
A man who subscribes himself "very sincerely" 
should be watched. It is a fairly safe generalization 
that the noisiest reformers all possess the tenden- 
cies they spend their lives in condemning. 



CHAPTEE VII 



SOCIAL PSYCHOLOGY 



Social psychology deals with the concerted be- 
havior of groups of individuals, and with the in- 
dividual's responses to his fellow man. 

Fellow Man as a Constant Situation 

We pay more attention to people than to any other 
part of our environment, and they furnish the occa- 
sion for our most elaborate behavior. The com- 
plex variety of their activities calls out in us a cor- 
respondingly rich assortment of responses. They 
are not passive objects, but are possessed of pent 
up tendencies to action that may be released at our 
slightest intervention. 

Every culture presents to man a distinctive, pecu- 
liar, and individual environment. An island in the 
South Seas has few resemblances to the make-up of 
a large city. The food, the habitation, and the out- 
door life of the Esquimaux differ greatly from those 
of the Louisiana Negro. Aside from such universal 
features of the environment as light, atmosphere, 
gravitation, and the uniformity of nature, which 

science attempts to describe, the one thing common 

220 



SOCIAL PSYCHOLOGY 221 

to all societies is fellow man, his anatomy, and his 
original nature. He is fairly constant from one gen- 
eration to another and fundamentally the same in all 
localities. For this reason there is an obvious fit- 
ness and propriety in the fact that, no matter where 
we may be born or who we may be, we respond to 
him with many instincts and habits common to hu- 
manity. He has always been the necessary object 
when we nurse as babies or love as adults. He is 
essential to our conversation and our quarrels. 
Without him we could not steal, murder, or disturb 
the peace. In his childhood he actuates us to nurse, 
shelter, and protect him. In short, because of his 
invariable structure, conduct toward him shows a 
persistent similarity in all societies. 

Otheb Pkevalent Situations 

Gravity, the earth's surface as a dwelling place, 
rain, sun, day, night, and the seasons, are relatively 
changeless situations in the history of the race. 
Vegetation, animal neighbors, and the sources of 
food, though somewhat the same in every epoch and 
every climate, show more variability. Houses, ve- 
hicles, tools, highways, industries, superstitions, 
ceremonies, recreations, language, and human in- 
stitutions in general, characterize particular times 
and places. According as these situations are gen- 
erally met with, a similarity of habits is established 
in all members of society. The possession of com- 



222 GENEEAL PSYCHOLOGY 

mon habits is what distinguishes a society from a 
mere aggregate of people. It is our task to discover 
the situations that accomplish this unification of re- 
sponse. Although the history of social machinery 
is the legitimate subject matter of sociology, man's 
creation, acceptance, and rejection of the artificial 
forms of society is a question for psychology. 

People show great similarity of behavior toward 
all objects commonly met with. They sit in response 
to chairs, sleep in beds, ride on trains, hoard money, 
distrust strangers, and wear clothes. There are 
other objects toward which the world as a whole does 
not respond so uniformly. Christians have a par- 
ticular way of acting toward the Bible, Americans 
toward their flag, women toward jewelry, the voodoo 
worshipper toward his fetish, certain groups toward 
their totems, and each household toward its belong- 
ings. The possession of similar response tendencies 
toward these objects defines and unifies a group. 

Places, like objects, elicit characteristic responses 
in the group. There is a conduct proper to church, 
to the dining-room, the graveyard, the school-room, 
the ball park. Dress that is proper on the bathing 
beach is inappropriate on the street car. While in 
a conveyance that moves vertically we remove our 
hats, but when in one that moves horizontally we 
feel no compulsion to do so. 

Times, like places and objects, stimulate us all to 
common action. We work by day and sleep by night ; 
we show good will toward men on Christmas and ill 



SOCIAL PSYCHOLOGY 223 

will on Hallowe'en; we are boisterous on July 
Fourth and sedate on Sunday. We glance at the 
clock and say it is time for the children to be in bed, 
or again we say it is time to get up. There is a usual 
time for tea, vacations, and formal calls. Birthdays, 
festivals, weddings, funerals, puberty ceremonies, 
and harvest time all demand their particular ob- 
servances, and unconventional behavior is on such 
occasions regarded as improper. 

We respond in a characteristic way to people rec- 
ognized as belonging to certain classes. We reserve 
deference, affability, or generosity for some, and ar- 
rogance, contempt, righteous indignation, or fear for 
others. Thus toward servants, policemen in uni- 
form, royalty, the graybearded, our betters, negroes, 
clergymen, prostitutes, blood-relatives, parents, 
criminals, reds, radicals, women, and children we ac- 
quire distinct and conventionally organized re- 
sponses. 

The efficiency of words depends upon their arous- 
ing similar reactions in everyone. Some words, like 
some places, objects, times, and classes of people, 
provoke not only a conventional response but arouse 
along with it an emotional drive that is particularly 
effective in unifying the crowd. The shrewd orator 
can rouse in his audience shame, awe, anger, pride, 
fear, or pity, by the proper choice of words or 
phrases or by employing a particular tone of voice. 
i ' Americanism, ' ' * * gentlemanly, ' ' " honorable, ' ' 
' ' profiteer,' ' "hell," are examples of drive-arousing 



224 GENERAL PSYCHOLOGY 

words. Titles are valued because they command re- 
spect. "Sir," "captain," "doctor," "professor," 
are titles that often carry an unmerited prestige. 
Academic degrees may be sought as an end in them- 
selves. Children hang their heads when told that 
they are "naughty," regardless of what they have 
done. Political catchwords stir up enthusiasm with- 
out much dependence upon their literal significance, 
and obscene words always secure the attention of 
polite people. 

Formation of Habits in Common 

The formation of common habits in a group is due 
to imitation and other forms of conditioned response 
and to adaptation. Given the proper environment, 
society as a whole may form almost any habit that it 
is possible for the individual to acquire. Outland- 
ish customs are not the fruit of anomalies of human 
nature in strange peoples, but merely the growth of 
a social inheritance guided by the strange world in 
which they live. 

Properly regulated behavior in a community in- 
volves something more than mere similarity of re- 
sponse among the individuals concerned. There is 
always to be found another sort of unity of action, 
which may be called complementary behavior. The 
way in which mother and child secure best results 
is not to behave alike but to behave differently. A 
mother acts in much the same way as mothers in gen- 



SOCIAL PSYCHOLOGY 225 

eral, and a child learns the way of children. Thus 
commonality of behavior attaches to classes of per- 
sons, but the proper interplay of responses of two 
persons of different classes necessitates not similar 
but reciprocal conduct. Indeed, cooperation between 
any two individuals demands complementary as well 
as like responses. Officer and enlisted man, physi- 
cian and patient, merchant and customer, master 
and servant, teacher and pupil, husband and wife, 
lawyer and client, each acts according to his con- 
ventional part in the relationship, but not neces- 
sarily in the same way as the person with whom he 
is holding social intercourse. 

Complementary behavior, when it occurs, is the 
inevitable result of the difference in situation con- 
fronting two people who are together, and of the dif- 
ference in their nervous organizations. For social 
organization, it is a happy fact that the behavior 
the baby shows toward his mother is useful in secur- 
ing him food,, and that the behavior he calls out in 
her is adjusted to the same end. These are, how- 
ever, no more mysterious facts than is the elasticity 
of the limbs of a tree a mysterious adjustment to its 
successful spilling of the wind. When these fortu- 
nate reciprocal relations occur in nature, they be- 
come fixed by the preservation of the organisms that 
show them. 

In the case of groups, as in the case of individuals, 
a habit response originally given to one situation 
may later be given to another situation, because of 



226 GENERAL PSYCHOLOGY 

the similarity or partial identity of the two. A par- 
ent learns to discipline his child and the child to obey 
his parent, and later, when the child becomes an 
adult, this coercive and submissive relation persists 
and is often detrimental to good government in the 
tribe. The "rule of the elders" in primitive cul- 
ture depends upon this undue pertinacity of chil- 
dren's habits of obedience and parents' habits of 
domineering, and involves a limitation of liberty for 
the young and an extension of privilege for the old. 

The treatment of the dead depends upon the per- 
sistence of habits formed toward the living. The 
name, the personal belongings, and the dwelling 
place of a deceased friend call out responses that 
are wholly inappropriate when he is gone. So, un- 
til these habitual responses of the survivors are dis- 
sipated, his ghost still walks. Weapons are put in 
his coffin and food is placed upon his grave. His 
name is spoken with caution and only his virtues are 
mentioned, lest he overhear. If he was a headman 
or chief, there still adheres to his sword some of his 
valor which makes the weapon deadly, and his man- 
tle gives to his successor a contagious wisdom. 

The sentimental value of belongings, the attach- 
ment we show to places in which we have spent 
happy days, the thrill aroused by the name of some- 
one we love, are all due to the former presence of 
situations in which these symbols were incidental 
features. The power of the symbols to call out these 
conditioned emotional responses makes men more 



SOCIAL PSYCHOLOGY 227 

willing to pay taxes on their homes and gives men a 
common interest in the symbolism of art, drama, 
and fiction. The transfer of response to substituted 
stimuli may also be due to a mere similarity between 
the new stimuli and the old. It is hard for us to mu- 
tilate the photograph of a friend, even though we 
realize that it is a mere bit of paper. Because 
women have learned to call little children "cute" or 
"dear," any object that is a miniature duplicate of 
something usually seen in large size is apt to be de- 
scribed in these words. We hear such expressions 
as, "What a dear little house," "What cute little 
biscuits." The smallest entry in the dog show al- 
ways has an attentive feminine audience. 

In childhood many responses are organized around 
human beings and are later given to situations in 
which fellow man does not figure. Children learn 
to seek their parents ' protection when in danger, or 
their assistance when in trouble. Parents and play- 
mates often interfere with the children's undertak- 
ings, and children learn to overcome this interfer- 
ence with supplicating, placating, and ingratiating 
behavior, with plausible excuses for misconduct, or 
by sharing their possessions with these older and 
stronger companions. To danger, pain, sickness, 
misfortune, ridicule, loneliness, or failure, the child, 
when he grows up, because of the tenacity of early 
habit, often responds in a childish way. 

If he is a benighted savage, he may not realize 
that sometimes inanimate nature alone is respon- 



228 GENERAL PSYCHOLOGY 

sible for Ids misfortune, and, seeing no human cause 
in the situation, may make up for its absence by in- 
venting or by accepting as present the evil spirits, 
demons, fays, and goblins that are part of all savage 
superstition. These he placates in childish fashion 
by gesture, cringing posture, words of praise, prom- 
ises of good conduct, circumspect behavior, and the 
offering of sacrifice. Because the storm wind is de- 
structive he assumes it to have a personality. The 
dangerous waterfall, the unsealed mountain, he 
treats as he would treat mighty human beings. When 
plague, sickness, drought, famine, flood, shipwreck, 
invasion, or other misfortune occurs, the tribe as a 
whole appeal to the spirits of their ancestors or to 
graven images for the assistance that, as children, 
they had learned to expect from parents. 

The combined appeal to the spirits is often sup- 
posed to be answered by a sign or augury. This 
gives confidence to the idolaters that they will be 
saved, and there results such a practical good as 
the passing of fear or the unification of group effort 
in meeting the misfortune. This persistence of child- 
ish reactions in the group makes fertile ground for 
the growth of certain vocations connected with cere- 
mony, divination, magic and sacrifice. Thus there 
are found groups of professional conjurers, magi- 
cians, medicine men, priests, and augurs who select 
and organize the ritual of festivals, incantation cere- 
monies, and temple life. 

In our own civilization childish responses in the 



SOCIAL PSYCHOLOGY 229 

face of danger or misfortune are by no means lack- 
ing. The adult male, his early tendencies to depend 
on nurse or mother long overlaid by habits of prac- 
tical self-reliance, will, when sick and taken to the 
hospital, exercise again his infantile responses. He 
tolerates with considerable satisfaction the personal 
service of his nurse, querulously demands attention, 
is jealous of other patients, becomes fretful upon 
small provocation, and is pleased by trifles. 

Man first shows generosity and kindliness in gen- 
eral to his family group because his early childhood 
is spent at home. The attachment of these response 
tendencies to the father, mother, brother, sister- 
situation makes it useful to employ family names to 
elicit these friendly responses toward society when 
the child becomes an adult and leaves his home. 
Hence we have the terms "brother man," "brother 
Elk," "little brown brother," "less fortunate sis- 
ter," "sister republic," "mother church," "the 
greatest mother of all," "mother country," "father- 
land," "city fathers," "father of his country," and 
many others. Because the husband-wife relation- 
ship does not exist for the child, these terms do not 
elicit responses of the sort just mentioned, and are 
not found to have this derived meaning in popular 
speech. 

Language includes names for many wholly mythi- 
cal situations, and society may react to these names 
as though the situations were real. In order to ex- 
plain the fact that these situations fail to stimulate 



230 GENERAL PSYCHOLOGY 

sense organs, the believer calls them immaterial, dis- 
embodied, incorporeal, astral, intangible, invisible, 
shades, or ghostly shadows, although such words af- 
ford no real explanation. The happy hunting ground 
and the Moslem paradise may conceivably be beyond 
the reach of our sense organs because of their great 
distance, but it requires more explanation to make 
plausible living beings who may work good or evil 
in a physical world, but who cannot affect the organs 
of vision or touch. The ghost in the dark is the 
frightened person 's rationalization of his fright ; the 
evil spirit is the unfortunate 's rationalization of his 
bad fortune ; just as the careless person explains the 
loss of a misplaced article by saying that a thief 
must have taken it, or just as the farmer explains 
the cool breeze in summer by saying that hail must 
have fallen in the vicinity. 

There is a tribe of Sioux in Manitoba who believe 
in the existence of a beast that has a convenient way 
of making itself invisible when looked at. 1 Many In- 
dians have been pursued by it along forest trails 
after dusk, to fall exhausted at the outskirts of the 
village. Similar beings rattle tambourines, write on 
slates, move tables, and speak through the lips of 
mediums. If the credulous Indian or the devotee 
of spiritism is asked why these odd beings do not 
perform in the sunlight, he takes refuge in the an- 
swer that it is the nature of the creatures to live in 

i Reported by W. D. Wallis. 



SOCIAL PSYCHOLOGY 231 

darkness. The influence of unseen spirits was the 
fundamental doctrine of witchcraft ; it explained to 
our forefathers the eccentric behavior of the insane, 
and even now is used by the uneducated to account 
for the tricks of the professional clairvoyant. As 
the Indian's flight from the noise in the dark is ex- 
actly the same as his flight would be from such a 
beast as the tribe has talked about, a noise has for 
him all the meaning that a real beast would have. 
In so far as the old dupe gives the same emotional 
response to his dead son's name on the lips of the 
medium, or to an alleged message written on a slate, 
that he would give to the son's presence, the situa- 
tion seems real to him. When we consider the ease 
with which an individual may fall victim to a belief 
in unrealities, though modern scientific method is at 
his disposal for checking up his belief, it is not sur- 
prising that, in cultures lacking the methods of 
science, credulity for erroneous tradition should be 
the rule. 

One result of society's conforming to manners and 
customs is that thereby men are able to react not only 
to what their neighbors have done but also to what 
they are about to do. This simplifies the world and 
makes life in communities possible. The amenities 
of polite society expedite our taking leave of our 
hostess, make ponderous explanations of our com- 
ings and goings unnecessary, and prevent much of 
the ill feeling that a candid analysis of situations 
would produce. Similarity of custom produces soli- 



232 GENERAL PSYCHOLOGY 

darity within a social group. The strangeness of 
contrasting custom seen in outsiders emphasizes 
caste and prevents the cohesion of diverse classes. 

The Spread of Tradition 

Tradition is the whole body of transmitted direc- 
tions for dealing with situations. Through the in- 
strumentality of words we may be properly prepared 
for events that we have not before experienced. Both 
common sense and science have this function, and 
tell us what to expect of objects and people. Applied 
science includes the description of the effects of situ- 
ations on society. Knowledge is passed down to us 
concerning what plants are poisonous, what to do 
when we wish to cross a river, when to plant corn, 
the way to trap animals, the kind of weather that is 
likely to follow an east wind, or how to insure good 
luck. 

Morality consists of traditional directions for con- 
duct, reenforced by social coercion. This coercion 
is accomplished not only by force but by approval 
and disapproval, praise and censure, friendliness 
and hostility. To the expression in word and action 
of these emotions in others we ourselves give emo- 
tional responses. It is these emotions in us that con- 
stitute the drive toward moral conduct. 

Approach and avoidance responses have their an- 
alogues in the vocabulary of morals ; and the words 
good and bad, right and wrong, brave and cowardly 



SOCIAL PSYCHOLOGY 233 

are stimuli to which we learn to respond in early 
childhood. Although social pressure is necessary for 
the original establishment of morals, when the moral 
habit is formed, it acts in the absence of coercion. 
We do not read another's postcard when we are 
alone because we have learned to avoid doing so 
while in the presence of others. The habit is re- 
enforced by the words we have heard applied to this 
ungentlemanly act. The student will find many in- 
teresting examples of moral tradition and moral 
habit in the anthropological literature concerning 
taboo. Morals are taught by anecdote and fiction as 
well as by precepts, proverbs, golden rules, and com- 
mandments. The words of the anecdote suggest the 
situation and arouse the emotions that govern the 
moral response. In this way fables and stories be- 
come the common heritage of society and usually in- 
volve the ambivalence of hero and villain. 

Traditions are built up through use. Tem- 
porary fads in conduct are absorbed into the teach- 
ing of society when they are fit, and eliminated when 
unfit. Even though aided by this process of selec- 
tion, tradition is always old-fashioned and lags some- 
what behind practical needs. Only after words are 
coined for new predicaments, and these words have 
wide acceptance, is it possible for tradition to oper- 
ate. 

An individual 's opinion includes some traditions 
but not others. It also includes a statement of facts 
based upon his own experience. Thus opinion is 



234: GENERAL PSYCHOLOGY 

built up from suggestion and from induction. It is 
usually impossible for the individual to experiment 
in the various sciences, so that he is forced to de- 
pend upon the statements of others for many of his 
views. Whether he accepts the unscientific state- 
ments of laymen or the conclusions of experts de- 
pends but little upon the intrinsic merit of their as- 
sertions. Statements are likely to be accepted that 
reenforce emotionally colored opinions already held, 
or that are uttered in such surroundings, by such 
persons, or in such words as arouse reenf orcing emo- 
tions. Acceptance is inhibited when the statements 
oppose existing beliefs, or when the situation in 
which they are heard arouses emotional resistance. 

Thus individual opinion may include belief in er- 
roneous causes due to the acceptance of tradition 
outside the domain of science. In this way supersti- 
tions result from the borrowing of opinions. These 
"idola theatri" may have widespread acceptance 
and pernicious social effects. People believe in the 
unlucky nature of Friday, or of the number 13 ; they 
even accept the divine right of kings, and the efficacy 
of homeopathic medicines, of amulets, of rain-mak- 
ing ceremonies, and of "character analysis." 

When we utter an opinion, we usually do so in re- 
sponse to a listener. He may be a friend, or an en- 
emy, a sweetheart or a rival, an employer or a serv- 
ant, a guest or an insurance agent. Our audience 
may be a crowd of one kind or another, a congrega- 
tion, a college class, or a political meeting. The 



SOCIAL PSYCHOLOGY 235 

words we say are always in part determined by the 
character of the listener. 

What we say is further determined by the thresh- 
olds of our verbal response tendencies. We have 
low thresholds for certain truth telling and for cer- 
tain lying. We have high thresholds for other state- 
ments, both true and false. That which "occurs" to 
us, whether it be expressed or inhibited, is a state- 
ment whose threshold is low. It usually describes 
things as we wish them to be, and is often designed 
to elicit from society a response that we desire. We 
have a low threshold for saying that the runner of 
the home team is safe on first, no matter whether this 
is true or false. The lonely child in bed has a low 
threshold for making the statement that he is thirsty, 
because this brings him temporary companionship. 
High thresholds attach to admitting that our family 
is of lowly origin or subject to insanity, to telling 
our hostess that we have had a tedious evening, or 
to using profane language. 

At times customary inhibitions to speech are re- 
moved, and unusual facilitations enter into the situa- 
tion. During a war, a political campaign, or a class 
conflict, partisan feeling and hostility toward oppo- 
nents drive us to inaccurate expression and weaken: 
many old inhibitions. In his appeal to the jury the 
attorney makes biased statements, and in the heat 
of eloquence the orator often garbles the truth. 

The responses of the listener are likewise deter- 
mined by the habits he has formed, as well as by the 



236 GENERAL PSYCHOLOGY 

external situation. He has tendencies to accept some 
statements and to reject others. The tendency to 
act upon or to repeat the assertions of others is 
called suggestibility, and when these assertions are 
false it is called credulity. The listener, like the 
speaker, is affected by partisan movements, and his 
suggestibility is modified accordingly. He is credu- 
lous of slander concerning political enemies and of 
eulogy of his leaders. Many Englishmen, but no 
Germans, believed a report that St. George led a 
British detachment to victory in one of the engage- 
ments of the late war. 

Opinion* Spreads from Mouth to Mouth 

Where the subject matter is outside the field of 
common sense, and thus not controlled by a common 
habit of statement in the group, or where common 
habits are disrupted by newly acquired social preju- 
dice, a statement of alleged fact undergoes succes- 
sive modifications as it is passed on from speaker to 
speaker. The cumulative error that increasingly at- 
taches to the story is a product of the uninhibited 
reaction tendencies of the successive narrators. A 
story so embellished is called a rumor. 

An act can not be imitated by anyone who has not 
formed a habit of acting in a like way. Inaccurate 
imitation results when this habit is not quite the 
same as the observed act that is the stimulus to im- 
itation. This fact is illustrated by a simple experi- 



SOCIAL PSYCHOLOGY 237 

ment. Write five digits such as 48275 on a card. 
Select a number of subjects and have the first one 
copy the writing on another card. Have the second 
reproduce the copy made by the first, the third the 
copy made by the second, and so on serially through 
the group. The digits written by the last subject will 
probably be 48275, although the form and size of the 
digits will be considerably altered. Now make a 
nonsense drawing of random lines and have it seri- 
ally transcribed by the same subjects. A compari- 
son of the original drawing with the final transcrip- 
tion will show very little likeness. The reason that 
the digits are reproduced throughout with fair ac- 
curacy is that all the subjects possess in common the 
habitual response of writing these symbols. The 
cumulative error in the serial transcription of the 
nonsense drawing is due to the absence of any com- 
mon habit. The modification of opinion as it is 
passed from one person to another is greatest when 
its expression is not a common habit in the group. 
Myth building occurs in essentially the same way. 
The myth grows as generations of narrators add to 
the account the expression of their own wishes. 
Through much addition and filtration its final form is 
a composite story voted on by many auditors. 

Human Institutions 

The foregoing discussion has dealt chiefly with 
shared environments that regulate in society be- 



238 GENEKAL PSYCHOLOGY 

havior that would otherwise be dispersed and unco- 
operative. Original nature, as well as a commonly 
experienced world, furnishes all men with tendencies 
to act alike. Of these tendencies, the emotional ex- 
pressions, depending only in part upon training for 
the order and the composition of their elements, are 
the most elaborate of our instinctive behavior pat- 
terns. Coenotropes with emotional components, such 
as flight, repulsion, curiosity, pugnacity, subjection, 
self-assertion, parental care, reproduction, gregari- 
ousness, acquisition, and construction, are often 
called " instincts.' ' Although they are habits and 
not instincts, they are acquired by everyone due to 
the similarity of environment in which all men are 
reared. Given our repertoire of natural response 
tendencies and a world order such as we have all 
lived in, our learned behavior inevitably combines 
with certain emotional expressions to form these al- 
most universally shared habit patterns. 

In sciences related to psychology it is often at- 
tempted to explain all human conduct in terms of a 
selected few of these coenotropes. It is then that the 
danger of giving the name " instincts' ' to these habit 
patterns and the necessity of challenging such an 
error are made evident. Freud's "Libido," Le 
Bon's "suggestion," Tarde's "imitation," Trotter's 
"gregariousness," and Veblen's "instinct of work- 
manship" are all conceived as vague, unanalyzed 
forces that drive men to action. Even when these 
widespread habit patterns are correctly analyzed and 



SOCIAL PSYCHOLOGY 239 

clearly defined, they furnish a wholly inadequate de- 
scription of human motives. They are at best rough 
and convenient terms, which we use to portray con- 
duct, but each of them applies to many forms of con- 
duct of diverse origin, and all of them taken together 
fall short of describing the majority of the acts of 
every day life. 

Human institutions are social habits maintained 
and directed by the material equipment that is used 
in their exercise. Banking, commerce, manufactur- 
ing, agriculture, transportation, education, slavery, 
marriage, war, the state, the church, the theater, 
and the press, all have their peculiar tools, and are 
established not only in custom but in legislation as 
well. It is futile to attempt a description of the ori- 
gin and maintenance of any one of these human in- 
stitutions in terms of component instincts, emotions, 
or coenotropes. The institutions are too complex to 
permit such analysis. Although certain emotions ob- 
viously predominate in some, emphasis on these pre- 
vailing emotions is likely to obscure the fact that 
nearly all man's capacities are involved in each one. 



APPENDIX 



APPENDIX 



CONSCIOUSNESS 



When two men are stung by a bee, an observer 
might describe both events in the same way. But 
if the observer happens to be one of these two men, 
he will describe the two events differently. In a 
way this is not surprising, because his eyes have wit- 
nessed the stinging of his fellow and his cutaneous 
sense organs have witnessed the stinging of him- 
self. Because those of his sense organs affected 
when he himself is stung are different from those 
affected when another is stung, his responses to the 
two situations are very dissimilar. 

Almost any man will say that the description of 
his behavior by another overlooks certain facts in 
the case. He will say that he knows more about the 
events that constitute his own life than anyone else 
knows. And he may say that the difference between 
being stung and seeing another stung is not entirely 
reducible to the difference in the sense organs af- 
fected and the responses evoked. 

A description of mind in terms of stimulation, neu- 
ral action, and responses is by no means the only 
one in use. There is another language, which the in- 
dividual may employ in describing the world as his 

243 



244 GENERAL PSYCHOLOGY 

own experience, and which includes terms that are 
useless in a description of behavior. This is the lan- 
guage of consciousness, and its importance is estab- 
lished by its popularity. 

Everyman's behavior includes conversation about 
his consciousness, though his consciousness is not 
open to the observation of others. In seeking in- 
formation about his private consciousness, he em- 
ploys the method of introspection, namely a minute 
description of his experience as he knows it at the 
time. The introspector may report in some such way 
as this: "The hunger pang seems to be located in 
my stomach ;" or, "The feeling of being about to 
say 'yes' involves less excitement than the feeling 
of being about to say 'no' "; or, "I have a clearer 
memory of the visual appearance of digits than of 
the visual appearance of letters. " 

Viewed as behavior, introspection is usually made 
up of verbal responses to organic states, and these 
responses are often indicative of what is taking place 
in the body. The hunger pang is actually coincident 
with a peristaltic contraction of the stomach. The 
consciousness of excitement is usually coincident 
with demonstrable changes in pulse, respiration, and 
muscle tone. It is probable that a clear imagery of 
digits is coincident with cortical action correspond- 
ing to a part of the cortical process that takes place 
when the digits are being read. 

For successful introspection, the thresholds of the 
verbal responses must be made unusually low by ex- 



CONSCIOUSNESS 245 

eluding distractions and by providing the subject 
with directions for self-observation. 



Consciousness and the Nervous System 

Consciousness is supposed to occur only when there 
is nervous action in certain parts of the cortex. The 
kind of consciousness that occurs depends upon the 
part of the cortex that is active. Destruction of the 
visual cortical area results in the loss of all visual 
sensations, and destruction of other sensory areas 
brings about a corresponding anaesthesia. Having 
conscious memories and ideas requires that certain 
parts of the cortex shall be intact. A decerebrate 
dog has presumably no sensations, thoughts, or feel- 
ings. 

Sensation 

If we analyze consciousness into its parts, the most 
conspicuous of these are sensations. "We receive 
a sensation of green when looking at the lawn, a sen- 
sation of sour when eating a pickle, a sensation of 
pain when we burn our hand, and sensations of move- 
ment when we walk. 

Sensations require the stimulation of sense or- 
gans and the conduction of nervous impulses to the 
sensory areas of the cortex. Sensations may be di- 
vided into classes according to the kind of sense or- 
gans involved. Thus we speak of visual sensations, 



246 GENERAL PSYCHOLOGY 

auditory sensations, or olfactory sensations. They 
may be distinguished also according to their qual- 
ities. A color may have such a quality as red or 
green. A taste may have the quality sour or bitter. 
Sounds may be high pitched or low pitched. Among 
these qualities degrees of likeness and difference may 
be distinguished. Blue seems more like green than 
like red. Each different quality of sensation is likely 
to be accompanied by a characteristic group of re- 
sponses. 

The qualities of tonal sensations may be ranged in 
a continuous series. Any tone may be assigned a 
place within the pitch scale, and we can pass from 
any one pitch to any other through imperceptibly 
small gradations. Other sensation qualities can not 
be arranged in such a series. 

The spectrum arouses a series of sensations that 
has some resemblance to the pitch scale, yet all but 
a few of these sensations are analyzable into two 
components. The only colors that can not be intro- 
spectively analyzed are red, yellow, green, and blue, 
and there is only one pure red, one pure yellow, one 
pure green, and one pure blue. Other colors seem 
to have more than one quality. 

The unanalyzable colors are sometimes called 
"physiological" colors, because each is supposed to 
be the sensation resulting from a certain kind of 
stimulation of a certain kind of sense organ. Almost 
all people agree in their identification of these physi- 
ological colors as points in the spectral series. Any 



CONSCIOUSNESS 247 

deviation from these points brings us to a color that 
seems to be a mixture of two physiological colors. 
Thus, although we speak of a series of greens in the 
spectrum, these may be divided into blue-greens and 
yellow-greens, which lie on either side of the physi- 
ological, or unanalyzable, green. 

A continuous qualitative series free from blends 
is not possible in sensations of vision, odor, taste, 
touch, warmth, cold, pain, movement, or in the or- 
ganic sensations. 

In the various combinations of pure sensation 
found in the consciousness of a given moment there 
are degrees of fusion or blending. Two sensations 
may so blend that only careful introspection will an- 
alyze them. A note and its octave sounded together 
on tuning forks, or the touch and temperature stim- 
ulation from a cold metal object, give such blended 
sensations. 

Two sensations occurring at the same time may 
fail to blend and may appear quite separate and dis- 
tinct. The color and odor of a flower do not blend, 
though they are experienced together. Introspective 
analysis of a sensation compound is possible only 
when its component sensations have been experi- 
enced separately. 

Sensations may combine not as blends but in the 
slightly less intimate association of patterns. Sen- 
sation patterns are produced by an aggregation of 
objectively separate stimuli, such as the parts of a 
picture, or the simultaneous bending of many joints. 



248 GENERAL PSYCHOLOGY 

The objective stimuli may also operate not at the 
same time but in succession, as when a melody is 
played, a sentence uttered, or a golf stroke executed. 
Any combination of easily separable sensations that 
is consciously felt to be a whole is called a pattern. 

Sensations have duration, and this corresponds 
roughly to the duration of the stimulus. 

The intensity of sensation depends mainly upon 
the intensity of the stimulus. There is a liminal 
threshold for sensation just as there is for responses, 
and the sensation does not occur unless the stimulus 
is of a certain intensity. In Weber's law the term 
"sensation" may be substituted for " response.' ' 

Summation effects are observable in sensation as 
well as in responses, and are brought about by the 
repetition of subliminal stimuli at short intervals. A 
sound that is too faint to be heard when it occurs 
once, may be heard when it is rapidly repeated sev- 
eral times. 

Sensations manifest initial torpor. After listening 
to a watch we may hear it at a greater distance than 
was originally possible. This is probably not wholly 
the result of a muscular adjustment of the sense 
organ. 

Continuous stimulation results in the fatigue of 
sensation, and is greater in the case of odor, taste, 
and touch than in the case of pain. 

The threshold of sensation may be altered in posi- 
tive and in negative adaptation in much the same way 
that the threshold of response is modified. The in- 



CONSCIOUSNESS 249 

frequent repetition of a subliminal stimulus, that 
is, one that is not sufficiently intense to arouse a re- 
sponse, raises the threshold for both sensation and 
response. When a stimulus that is above the thresh- 
old is repeated to the point where fatigue interferes 
with the response, both the response threshold and 
the sensation threshold may be raised. When a re- 
sponse threshold has been raised as the result of 
the repeated action of an inhibiting stimulus, the 
threshold of sensation will be raised also. 

An ascetic is originally prevented from enjoying 
the luxuries of life by the influence of his austere 
companions. If he remains an ascetic, it is because 
one of two things has happened. He has either come 
to disregard the things of the flesh, in which case he 
develops negative adaptation, both of sensation and 
of response, to these situations, or these situations 
have produced in him a conditioned response of ac- 
tive antagonism, in which case his threshold of sen- 
sation is lowered rather than raised. 

Positive adaptation of sensation always involves 
positive adaptation of some response. This may be 
merely an increased tendency to orientation. On the 
other hand, practice in responding to situations may 
result in a decreased intensity of sensation. That is, 
positive adaptation of response may be accompanied 
by negative adaptation of sensation. If we have at- 
tained skill on the typewriter we may, when writing, 
be almost unconscious of what we are doing. This 



250 GENERAL PSYCHOLOGY 

diminution of consciousness accompanies freedom 
from inhibitions. 



Emotion and Affection 

Introspective psychology has not fully decided the 
question whether emotional consciousness can be 
identified with organic sensations, the results of in- 
ternal responses. There is a growing tendency, how- 
ever, so to regard them. Though essentially sensa- 
tional, they may be made up in part of memories of 
past organic experiences. 

Among the affective states of consciousness, the 
most generally recognized are pleasure and unpleas- 
ure. These are by some regarded as qualities of 
sensation, and by others as separate conscious ele- 
ments. 

Images 

There is always a short interval between the stim- 
ulation of a sense organ and the occurrence of the 
sensation. This time is consumed in overcoming in- 
ertia in the sense organ and in the transmission of 
the impulse from sense organ to brain, and is known 
as the latent period of sensation. After the stimulus 
ceases, the sensation continues for a very short time, 
and this interval between the end of the stimulus and 
the end of the sensation is called the period of lag of 



CONSCIOUSNESS 251 

the sensation. When strong stimuli are used, the 
period of lag is greater than the period of latency. 

The lag of sensation may be divided into two parts. 
The first is due to the continued action of the sense 
organ after the stimulation has ceased, and is called 
the positive after-image. A second part following 
this is probably due to a similar momentum in sen- 
sory areas of the brain, and is called primary mem- 
ory. This whole period of lag may last for but a sec- 
ond or two. It accounts in part for our ability to 
distinguish two tones of almost the same pitch 
sounded in quick succession, when this would be im- 
possible if a longer time intervened between the two. 
It also accounts for continuous sensation from the 
intermittent stimulation of a motion picture. 

After primary memory has disappeared, what is 
known as a memory image may appear in conscious- 
ness. Such images may occur many years subse- 
quent to the original sensation. Some people retain 
clear images of childhood experiences and probably 
everyone has memory images to a greater or less ex- 
tent, although there are great individual differences 
in this kind of retention. In general, the memory 
image is clearer for recent experiences, for experi- 
ences that are novel, for experiences that are emo- 
tionally reenforced, and for experiences that have 
been long continued. A day spent over the micro- 
scope is usually followed by clear memory images of 
the material studied. "We remember vividly an acci- 
dent or a hairbreadth escape, our first kiss or our 



252 GENERAL PSYCHOLOGY 

first day at school, the hospital room in which we 
spent two weeks, or the pocket knife we carried for 
years. In brief, our memory images are clear in pro- 
portion to the recency and duration of the original 
experiences and in proportion to the attention that 
was given to them. 

Memory images and ideas are never wholly 
divorced from response tendencies. Overt action 
may or may not follow thought, but consciousness 
is most in evidence while a response is pending. De- 
layed responses are usually attended by a rich con- 
scious experience. When responses follow immedi- 
ately upon stimulation, sensations are usually 
shorter lived and do not wholly lose their initial 
torpor. 

Association or Ideas 

Before the science of behavior was developed, cer- 
tain laws of association were formulated to describe 
the origin of the sequence of ideas. These laws state 
that in any train of thought one idea follows another 
only when the experiences from which these ideas re- 
sult have occurred in certain relationships. It was 
shown that if two experiences occur in immediate 
succession, the first, being repeated either as a sen- 
sory experience or as a memory, was capable of call- 
ing up the other. When we smell or think of the 
odor of roses, we are reminded of their visual ap- 
pearance because roses have been smelled and then 
seen many times. When we see lightning or even think 



CONSCIOUSNESS ' 253 

about it, the idea of thunder is apt to come to mind. 
The law describing this sequence is that of associa- 
tion by temporal contiguity. The law that describes 
associations as due to spatial contiguity is reducible 
to the first law. Objects experienced together in 
space are also experienced adjacent in time. Even 
where two experiences, though separated in time, oc- 
cur in the same place and are later associated, such 
as becoming acquainted with two individuals on sepa- 
rate occasions at the house of a friend, the matter 
may be described as a double temporal association. 
Cause and effect become associated ideas, but only 
when these ideas or the experiences that underlie 
them have been known to us in immediate succes- 
sion. Ideas that are similar tend to arouse each 
other because they are partially identical. Thus rats 
may make us think of mice on account of their similar 
shape and odor, though the two have never been seen 
together; cigars may remind us of cigarettes be- 
cause both are made of tobacco ; red flowers may call 
to mind blood. Some consecutive ideas that seem 
to be associated on the basis of their similarity show 
a likeness that is not so evidently an identity of ele- 
ments. There is, for example, a similarity between 
any musical note and its octave, or between the colors 
red and violet. Though in these cases the physical 
stimuli are far from similar, the neural mechanisms 
they stimulate are probably in part identical. 

These laws of association state for ideas what the 
conditioned response describes in behavior. 



254 GENERAL PSYCHOLOGY 

Cortical activity must underlie the apparently ran- 
dom train of thought found in revery and dreams. 
It is clearly necessary that the nervous energy for 
such a chain of processes must come from some- 
where. Is there any reservoir of energy that is con- 
stantly available for the maintenance of cortical 
processes in general? 

The energy derived from looking at a mutton chop 
does not cause us to think of the logarithm of seven 
because this decimal was never thought of while the 
mutton chop was in sight. The mutton chop does 
not contribute energy to cortical processes that have 
not previously taken place while it is being looked at. 

There are, however, certain forms of stimulation 
that are almost constantly present and, for this rea- 
son, have in the past accompanied practically all our 
acts and all our thoughts. These are the stimuli 
resulting from respiration, heart beat, and the 
muscle strain involved in maintaining equilibrium. 
As these stimuli are almost always acting, every act 
and every thought is in some degree conditioned 
upon them. Thus many cortical pathways are open 
to these impulses and the impulses are available to 
maintain many trains of thought. An infrequent 
stimulus, such as the mutton chop, could energize 
only a few ideas. 

Stimuli that are constantly present tend to be fol- 
lowed by so many thoughts and responses that they 
are regularly followed by no one in particular, ex- 
cept, perhaps, those that have most recently occurred 



CONSCIOUSNESS 255 

and thereby have a low threshold. This may be an 
explanation for the tendency of recent thoughts and 
responses to recur in the absence of specialized stim- 
ulation. When we go to bed, the organic stimuli that 
have accompanied our conscious experiences of to- 
day are more likely to revive memories of to-day 
than memories of yesterday, because the thresholds 
of to-day 's ideas are lower than those of a time more 
remote. Thus the imagery of dreams is of events of 
the day just past and of such events of childhood as 
at that time established for themselves a perma- 
nently low threshold. Thought is directed when the 
stimuli that are present have attached to them only 
a few definite responses. The undirected nature of 
dreams and of waking revery is to be accounted for 
in large part by the absence of varied and unusual 
stimulation and by the ever present residuum of or- 
ganic stimuli. 

That most people are unable to recall their dreams 
is probably due to the fact that few experiences of 
waking life were present during the dream and so 
cues for dream revival are lacking. 

Imagination 

Just as two response tendencies may combine into 
a compromise response when simultaneously aroused, 
so two or more memories simultaneously excited may 
be condensed into a resultant idea, thought, concept 
or notion. 



256 GENERAL PSYCHOLOGY 

In imagination there come into consciousness 
thoughts and memory images more or less distorted. 
This sequence of imagery may seem wholly casual 
upon first inspection, but on careful analysis turns 
out to be determined first of all by the sequence of 
experiences of which these memories are the 
* ' copies. ' ' No memory is isolated, but each memory 
is always introduced by either a preceding memory, 
or a sensation, or a subliminal stimulus. The image 
follows such an event because it, or the past sense 
experience to which it corresponds, has previously 
followed this event. 

The sequence of previous sense experiences is not 
the only factor in determining the train of thought. 
The train of thought takes one direction at one time 
and another direction at another time, because of 
the varying resistance at synapses. In behavior, 
although many responses are attached to a single 
stimulus, usually, only one response of lowest thresh- 
old is elicited. In conscious thought, although any 
idea has many associates, not all possible asso- 
ciates appear each time the idea comes to mind. The 
threshold of any associate varies from time to time. 

Attention 

Objectively, attention is the orientation of sense 
organs toward the source of stimulation, the lower- 
ing of the response threshold, and the cessation of 
movements that do not serve to explore the object 



CONSCIOUSNESS 257 

that is attended to. Subjectively, attention is the 
dominant presence in consciousness of either a sense 
experience or an idea, or of a group of sensations 
or ideas that have a systematic relation to each other. 
As in the case of behavior, subjective attention in- 
volves the disregard of distracting stimuli. The 
clearness of attentive consciousness that results from 
the absence of rivalry is often accompanied by sensa- 
tions from the muscular contraction involved in 
orientation arid preparation for action. These sen- 
sations account for the " effort' ' that seems to char- 
acterize the conscious state of attention. 

The sensation or idea attended to is determined 
by the conductivity of rival pathways in the nervous 
system, and by accompanying facilitations and in- 
hibitions. After the lapse of a few seconds, a 
sensation loses its intensity or an image its 
clearness. This is analogous to other forms of fa- 
tigue and invites description in terms of increased 
threshold. After a brief time the threshold is again 
lowered and the sensation or image may recur with 
its original clearness. The pulse of attention usually 
lasts less than a second. Attention is most evident 
when there is a balancing of response tendencies. 

PEKCEPTIOlSr 

Perception as a conscious event may be analyzed 
into two parts. On the one hand there are the sensa- 
tions that result from sense-organ stimulation, and, 



258 GENERAL PSYCHOLOGY 

on the other hand, there are certain components that 
are non-sensory, but which blend with the sensations. 
These non-sensory components correspond to mem- 
ory images, though they are too well fused with the 
sensations to permit of easy analysis. Herbart gave 
the name apperception to the non-sensory compo- 
nent of perception. 

One of the common errors of careless introspec- 
tion is to mistake the organic sensations of a per- 
ceptual response for apperception. When we see a 
snake, the sensory part of the perception is by no 
means limited to visual sensations, but includes sen- 
sations produced by muscular and visceral changes. 

The Unconscious 

Sometimes we are conscious of what we are doing, 
and sometimes we are not. When we enter a strange 
house, when we answer a difficult question, when we 
eat unfamiliar food, or when we are overtaken on a 
railroad trestle by an approaching train, we are de- 
cidedly conscious of the situation, if not of the acts, 
we perform. Usually vivid memories of these situa- 
tions persist and we are able to describe the things 
that have happened. 

Consciousness of our own acts is most likely to re- 
sult when we are doing something to ourselves, and 
are thus in a position to observe our own movements 
and our own bodily states. When a man removes 
a splinter from his own finger, tries on a new suit, 



CONSCIOUSNESS 259 

or learns a new dance step, he has a clear conscious- 
ness not only of the external situation but also of 
what he is doing. 

On the other hand, a great many situations and a 
great many acts do not produce a state of conscious- 
ness. Light from a multitude of surrounding objects 
affects the retina, sounds stimulate the ear, and ob- 
jects touch the skin, often without our knowing any- 
thing about it, even though they may cause re- 
sponses. Frequently we may take articles from our 
pockets, or walk some distance along a familiar 
street, or draw diagrams on the wall of a telephone 
booth, without being at all conscious of acting. The 
great majority of the movements we make certainly 
leave behind them no conscious memories and prob- 
ably arouse no consciousness at the time. Delayed 
responses, compromise responses, and blocked emo- 
tional expression nearly always have a conscious ac- 
companiment. In other words, conscious states are 
usually found when there is interference among re- 
sponse tendencies. 

Although acts unaccompanied by consciousness 
might well be called unconscious acts, the term, ' i the 
unconscious," is generally reserved as a classifica- 
tion and as a somewhat too easy explanation for acts 
whose lack of preceding conscious motive, whose 
lack of conscious accompaniment, or whose lack of 
resulting conscious memory is a matter of surprise. 
The man who has a horror of Gothic windows but 
who does not know why, is said to have an uncon- 



260 GENERAL PSYCHOLOGY 

scious motive for his fear. It might possibly be dis- 
covered on investigation that as a baby he strayed 
away and was lost in a gloomy cathedral, but has 
retained no conscious memory of this occurrence. 

Most of our motives are unconscious in the sense 
that we are not aware of the circumstances under 
which our reaction tendencies were established. We 
are also unable to say what kind of emotional re- 
enforcement drives us to act as we do. The parlor 
maid who accidentally breaks the ornate vase, the 
dusting of which has often caused her annoyance, is 
supposed by Freud to be actuated by a subconscious 
motive in her act of destruction. Many psycholo- 
gists, however, are content to describe this occur- 
rence as an awkward act resulting from the conflict 
of two tendencies, both of which are aroused by the 
sight of the vase. One of these is a tendency to dust 
the object, and the other is a tendency to smash the 
annoying thing. It is by no means necessary to as- 
sume an unconscious mind that plots evil against a 
more righteous consciousness. 

An anomalous lack of conscious accompaniment is 
seen in the automatic writing performed by the hand 
of an hysteric. He is unconscious of his act and his 
attention seems to be fully engaged on other matters. 
This is described as an automatism. 

The absence of memory for events that would 
usually be remembered is called amnesia. 



BIBLIOGRAPHY 

Aristotle : 

De sensa, 436b. 
Blanton : 

"Behavior of the Human Infant," Psychological Re- 
view, 1917, pp. 456-483. 
Cannon, W. B. : 

Bodily Changes in Pain, Hunger, Fear, and Rage, New 
York, 1915, 
Colvin, S. S. : 

The Learning Process, New York, 1915. 
Darwin, Charles : 

The Expression of the Emotions in Man and in Ani- 
mals, New York, 1892. 
Doll: 

"Anthropometry as an Aid to Mental Diagnosis/' Re- 
search Publication 8. Training School, Vineland, 
New Jersey, 1916. 
Ebbinghaus, Hermann: 

Memory. Publications of Teachers College, Columbia, 
New York, 1913. 
Goldmark, Josephine : 

Fatigue and Efficiency, Russell Sage Foundation, 1912, 
p. 71. 
Herrick, C. J. : 

Introduction to Neurology, Philadelphia, 1915. 
Hill, Rejall, and Thorndike : 

Practice in the Case of Typewriting, Pedagogical Semi- 
nar, 1913, pp. 516-^29. 

HOLLINGWORTH, H. L. : 

The Psychology of Functional Neuroses, New York, 
1920. 

261 



262 BIBLIOGEAPHY 

Holmes, J. J. : 

Studies in Animal Behavior, Boston, 1916. 
Hunter, W. S. : 

The Delayed Reaction in Animals and Children, Ani- 
mal Behavior Monographs, 1913, No. 1. 
James, William: 

Principles of Psychology, New York, 1890. 
Jennings, H. S. : 

The Behavior of Lower Organisms, New York, 1906. 
Ladd, G. T., and Woodworth, R. S. : 

Elements of Physiological Psychology, New York, 1911. 
Lashley, K. S. : 

"A Simple Maze; with data on the relation of the dis- 
tribution of practice to the rate of learning," Psy- 
chobiology, 1918, pp. 335-367. 
The Acquisition of Skill in Archery, Carnegie Insti- 
tute, 1915. 
Lyon, D. 0. : 

Memory and the Learning Process, Baltimore, 1917. 
Locke, John : 

Essay Concerning Human Understanding. 
Meumann, Ernst: 

Psychology of Learning, New York, 1913. 
Pechstein, L. A. : 

Whole vs. Part Methods in Motor Learning, Psycho- 
logical Monographs, 1917. 
Peterson and Eainey : 

"Beginnings of Mind in the New Born,'' in the Bul- 
letin of the Lying-in Hospital of the City of New 
York, 1910. 
Preyer, W. T. : 

The Mind of the Child, New York, 1905. 
Pyle: 

"Economical Learning," Journal of Educational Psy- 
chology, 1913, pp. 148-158. 



BIBLIOGRAPHY 263 

Pyle and Snyder : 

"The Most Economical Unit for Committing to Mem- 
ory,' ' Journal of Educational Psychology, 1911, pp. 
133-142. 
Sherrington, C. S. : 

The Integrative Action of the Nervous System, New 
York, 1906. 
Singer, E. A., Jr. : 

"Mind as an Observable Object," Journal of Philoso- 
phy, 1911, p. 180; also 1912, p. 206; "Consciousness 
and Behavior," Journal of Philosophy, 1912, p. 15; 
"The Pulse of Life," Journal of Philosophy, 1914, 
p. 645; "On Sensibility," Journal of Philosophy, 
1917, p. 337. 
Smith, Stevenson: 

"The Limits of Educability in Paramoecium, " Jour- 
nal of Comparative Neurology and Psychology, 1908, 
p. 503; "Regulation," Journal of Philosophy, 
1914. 
Spalding : 

Nature, vol. 12, p. 507. 
Thorndike, E. L. : 

Animal Intelligence, New York, 1911. 
Educational Psychology, New York, 1918. 
"Fatigue in a Complex Function," Psychological Re- 
view, 1914, pp. 402-407. 
"Notes on Practice, Improvability, and the Curve of 
Work," American Journal of Psychology, 1916, pp. 
550-565. 
Triplett : 

"The Educability of the Perch," American Journal 
of Psychology, vol. 2, p. 419. 
Twitmyer : 

A Study of the Knee Jerk, Philadelphia, 1902. 



264 BIBLIOGRAPHY 

Watson, John B. : 

Psychology from the Standpoint of a Behaviorist, 
Philadelphia, 1919. 
Watson, John B., and Rayner : 

' ' Conditioned Emotional Reactions," Journal of Ex- 
perimental Psychology/' 1920, pp. 1-14. 
Wood worth, R. S. : 

Dynamic Psychology, New York, 1918. 



INDEX 



Act, 44 

Adequate stimulus, 3 
Adrenal glands, 37 
Adrenin, 38 
Affection, 250 
Afferent neurone, 27 
Alimentary tract, 36 
sense organs in, 21 
Ames, 217 
Amnesia, 260 
Apncea, 208 
Apperception, 258 
Approach responses, 119 ff, 

142, 232 
Aristotle, 6 

Association of ideas, 252 
Associative inhibition, 99 
Attack, 142 
Attention, 204, 256 
Automatism, 260 
Autonomic nervous system, 24, 

see Fig. 8 
Avoidance reaction, 118, 119/, 

142, 232 
Awkwardness, 258 
Axis of vision, 8 



Babies, behavior of, 139 ff 

Basilar membrane, see Fig. 5 

Behavior, 3 

dependent on bodily struc- 
ture, 3 

Behavioristic description of 
mind, 1 

Belief, 195 

Binocular accommodation, 174 

Blanton, 51 



Blinking, 52 
Blocking, 212, 216 
Brain, 23, 25 



Central nervous system, 23 
Cerebral cortex, 26 
Cerebral hemispheres, 25 
Chain reflex, 54^, see Fig. 13 
Childish responses, persistence 

of, 227 ff 
Choice, 194 
Ciliary muscles, 10 
Cleanliness, 54 
Cochlea, 15, see Figs. 4 and 5 
Coenotropes, 134, 238 

definition of, 137 
Cold organs, 19 
Cold, paradoxical, 19 
Cold, stimulus to, 19 
Collecting, 138 
Color, 11 
Color vision, 12 
Colvin, 111 
Common modes of behavior, 

145, 222, 224 
Compromise responses, 111, 170 
Complementary behavior, 224 
Conductivity, 5, 205 
Conflict, 216 

Conditioned response, 88 
Cones in retina, 12 
Connecting neurones, 27 
Consciousness, 1, 243 

and nervous system, 245 
Consummatory response, 60, 
62, 203 

lacking in play, 152 



265 



266 



INDEX 



Contiguity, 253 
Convergence, binocular, 14 
Conviction, 195 
Coordination, 129/ 
Cornea, 8 
Credulity, 236 
Crying, 51 

Cumulative error, 237 
Curiosity, 156 
Custom, 224, 231 



Darwin, 37 

Dead, treatment of, 226 
Delayed reaction, 198 
Delusion, 197 
Depressing emotions, 211 
Differential threshold, 42 
Digestion, 36 
Distance receptors, 6 
Distraction, 45 
Doll, 140 

Drainage, 97, 99, 211 
Dreams, 218, 255 
Drive, 134, 210 ff 
Dunlap, 104 
Duration, 248 



Ear, 14 

stimuli to, 15 
Ebbinghaus, 105 ff 
Effectors, 3, 5 
Efferent neurone, 28 
Electric current, as stimulus, 4 
Emotion, 250 
Emotional expression, 2, 37 

in infants, 54 
Emotional reenforeement, 123 

in play, 153 

in curiosity, 156 
Emotional responses, condi- 
tioned, 91 ff 
Enteric responses at birth, 51 
Enteric tract, 36 
Equivocal stimuli, 167, 191 



Events, perception of, 161 

Exhibitionism, 215 

Exteroceptors, 6 

Eye, 8 

dark adapted, 14 
-hand coordination, 50 
movements, instinctive, 51 
stimuli to, 11 

Eyes, convergence of, 8 



Facilitation, 44 

by conditioning stimuli, 95 
Fatigue, 87, 248 
Fear, 82, 134 

of darkness, 155 

of strangers, 154 
Fellow-man, 220, 227 
Fixation, 173 
Fixed idea, 217 
Following, 131, 143 
Forgetting, 79, 109, 111, 218, 

see Fig. 25. 
Fovea, 12 
Free will, 209 
Freud, 218 
Fusion, 247 

binocular, 14 



Glands, 3 

adrenal, 37 
Goldmark, 87 
Greasiness, perception of, 172 



Habit, inheritance of, 72 
Hallucination, 168 
Hardness, perception of, 171 
Herrick, 102 
Hill, 79 

Hollingworth, 93 
Homesickness, 155 
Hunger, 21 
Hunter, 191 
Hysteria, 216 



INDEX 



267 



Illusion, 168 
Images, 250 
Imagination, 255 
Imitation, 130^, 163 
Individual differences, 70 ff 
Inheritance of habit, 72 
Inhibition, 45 

associative, 99 

mutual, 46 
Initial torpor, 85, 248 
Instinct, 48, 136 

classification of, 60, 64 

definition of, 48, 145 

transiency of, 145 
Intelligence tests, 71 
Intention, 198, 209 
Interoceptors, 6, 20 
Intervention, responses of, 33, 

35 
Institutions, 239 
Introspection, 244 
Iris, 8 

James, 82, 143 
Jennings, 118 
Judgment, 190^ 



Kinesthetic organs, 23 
stimulus to, 23 



Ladd and Woodworth, 8 
Lag, 251 
Language, 162 

acquisition, 132 

in judgment, 195 

sounds, 51 

subvocal, 162 
Lashley, 79, 89, 116 
Latency, of response, 198 
Latent period, 250 
Laughter, 214 
Learning, 75 ff 

neural basis of, 97, see Fig. 
19 

whole vs. part, 113 



Lens, 8/ 

Liminal stimulus, 39 
Locke, 90 
Locomotion, 33 
Lyon, 115 

Maintaining stimuli, 61, 69 

Masochism, 215 

Maturation, 48, 50 

of premature infants, 49 

Memorizing, 115 

Memory image, 251 

Memory of childhood, 213 

Mental tests, 71 

Meumann, 110 

Mind, 243 

Monocular accommodation, 174 

Motives, 198 ff 

Motor nerves, 23 

Morality, 232 

Movement produced stimuli, 
130, 204, 206 

Muscles, 3 

Muscle and tendon sense or- 
gans, 23 

Muscles, involuntary, 24 

Negative adaptation, 80, 248 

neural basis of, 99 
Nervous impulses, 4 
Nervous system, 3, 23 
Nest building, 67 
Neural arc, 4, 27 
Neurones, 4 

efferent, 27 
Nonsense syllables, 105 
Nose, 17 
Noise, 182 
Nursing, 56/ 



Observation, 162 

Odor, sense organs of, 17, see 

Fig. 6 
Opinion, 233 
spread of, 236 



268 



INDEX 



Orientation, 33, 119, 199, 204 
Otoliths, 22 
Overcorrection, 218 
Overlapping of responses, 

128 
Overlapping of situations, 129, 

161 



Pain organs, 19 

Pain, stimulus to, 20 

Papilfce, 20 

Paramoecium, 117 

Pathways, neural, 23, 29, see 

Fig. 12 
Patterns, 247 
Pavlow, 89 
Peckham, 59 
Pechstein, 115 
Perception, 158 ff, 257 

kinesthetic and static, 186 

of language, 178 

of objects, 178, 181, 222 

of occasions, 222 

olfactory, 183 

of people, 223 

of places, 222 

of space, 172 ff, 180 

of time, 187 

touch, 186 
Peripheral nervous system, 23, 

see Fig. 8 
Peristalsis, 36 
Perseveration, 112 
Physical object, man a, 1, 175 
Play, 148 ff 
Pleasure, 250 
Positive adaptation, 76jff, 248 

neural basis of, 97 
Practice curve, see Fig. 17 
Practice, distribution of, 115 

in serial response, 105, 106 ff, 
see Figs. 22 and 23 
Precurrent responses, 209 

in play, 153 
Pressure, as stimulus, 4 
Primary memory, 251 



Proprioceptors, 7, 21 
Psychoneuroses, 93 
Pupil, 8 

Puzzle box, 118, 124 ff 
Pyle, 115 
Pyramidal tracts, 28 



Quality of sensation, 247 



Rage, 37 
Rayner, 91 
Receptors, 3 
Reasoning, 195 

Reenforcement, emotional, 123 
Reflex, 49 

arc, 28 

arcs of higher level, 49 

conditioned, 89 

grasping, 52 

salivary, 89 

scratch, 30 

time of, 190 

tongue, 30 
Rejall, 79 
Respiration and voluntary 

movement, 125 
Response, absence of utility in, 
32 

compromise, 46 

conditioned, 88 

delayed utility of, 31 

internal, 36 

precurrent, 62, 67, 209 
in play, 153 

regulatory, character of, 5, 
28 

serial, 100 ff, 116 
Responses, incompatible, 100 

overlapping of, 128 
Right-handedness, 140 
Retina, 8, 11 

fatigue of, 13 

photochemical substances in, 
12 
Rods in retina, 12 



INDEX 



269 



Roughness, perception of. 171 
Rumor, 236 



Saccule, 22, see Fig. 4 
Sadism, 215 

Saving method, 108, see Fig. 24 
Sclerotic, 8 

Semicircular canals, 21, see 
Fig. 4 

stimulus to, 22 
Secretion, action on muscles, 38 
Sensation, 245 #* 
Sense organs, 3 

classes of, 6 

position of, 5 
Sensory nerves, 23 
Sensory neurone, 27, see Fig. 

10 
Serial response, 100 ff, 116 
Sherrington, 6, 9, 46, 102, 228 
Similarity, association by, 227, 

253 
Singer, 2 
Situation, 44, 221 
Skeletal muscles, 23 
Smiling, 52, 131 
Smith, 30, 126 
Sneezing, 51 
Snyder, 115 
Sociology, 222 
Social psychology, 220 ff 
Spalding, 139, 143 
Spinal cord, 23, 25, see Fig. 9 

columns in, 25 
Spirits, 228 
Static organs, 22 

stimulus to, 23 
Stereognosis, 172 
Stickiness, perception of, 172 
Stimuli, 3 

adequate, 3 

conditioning, 125 

kinds of, 4 

maintaining, 69 

movement-produced, 55 

proprioceptive, 101 



Stimulus-response mechanism, 

39 
Stimulus-response mechanisms, 

interaction of, 43 
Sublimination, 214 
Suggestibility, 236 
Summation of stimuli, 40, 84, 

248 
Summation of diverse stimuli, 

40 
Superstition, 228, 234 
Suspensory ligament, 9 
Swimming, not instinctive, 54 
Symbols, 226 
Synapse, 4, 97 



Taboo, 233 
Taste and smell, 20 
Taste organs, 20 
Taste, stimuli to, 20 
Thinking, 1 

subjective nature of, 2 
Thirst, 21 

Thorndike, 79, 88, 118 
Thought, train of, 253, 256 
Threshold, 76, 119 
Threshold stimulus, 39 
Throwing, 140 
Tickling, 172 
Timbre, 182 
Time perception, 187 
Tone, 181 

Touch corpuscle, 18, see Fig. 7 
Touch, organs of, 17 
Tradition, 232 
Trial and error, 117^ 
Trial and error simplification 

of responses, 119 
Triplett, 83 

Tympanic membrane, 14 
Twitmyer, 89 



Unconscious, 258 
Utricle, 22, see Fig. 4 



270 



INDEX 



Visceral muscles, 36 
Visual stimuli, responses 

134, 142 
Vision, distant, 11 

double, 14 

near, 11 
Volition, 205 



Walking, 139 
Warmth organs, 18 



to, 



Warmth, stimulus to, 19 

Wasp, 59 

Watson, 50, 54, 89, 91, 134, 141 

Weber's law, 42, 248 

Wetness, perception of, 171 

Wilson, 112 

Wish, 203 

Wish, fulfillment, 218 



Yawning, 51 



(l) 



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